High performance UV and heat crosslinked or chain extended polymers

ABSTRACT

Disclosed is a composition comprising a polymer with a weight average molecular weight of from about 1,000 to about 100,000, said polymer containing at least some monomer repeat units with a first, photosensitivity-imparting substituent which enables crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer also containing a second, thermal sensitivity-imparting substituent which enables further crosslinking or chain extension of the polymer upon exposure to temperatures of about 140° C. and higher, wherein the first substituent is not the same as the second substituent, said polymer being selected from the group consisting of polysulfones, polyphenylenes, polyether sulfones, polyimides, polyamide imides, polyarylene ethers, polyphenylene sulfides, polyarylene ether ketones, phenoxy resins, polycarbonates, polyether imides, polyquinoxalines, polyquinolines, polybenzimidazoles, polybenzoxazoles, polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixtures thereof.

This application is a divisional of Application No. 09/221,690, filedDec. 23, 1998, which is a divisional of Application Ser. No. 08/705,488,filed Aug. 29, 1996 U.S. Pat. No. 6,124,372.

BACKGROUND OF THE INVENTION

The present invention is directed to curable compositions havingimproved characteristics. The present invention is also directed toimproved photoresist compositions and to improved thermal ink jetprintheads. One embodiment of the present invention is directed to acomposition comprising a polymer with a weight average molecular weightof from about 1,000 to about 100,000, said polymer containing at leastsome monomer repeat units with a first, photosensitivity-impartingsubstituent which enables crosslinking or chain extension of the polymerupon exposure to actinic radiation, said polymer also containing asecond, thermal sensitivity-imparting substituent which enables furthercrosslinking or chain extension of the polymer upon exposure totemperatures of about 140° C. and higher, wherein the first substituentis not the some as the second substituent, said polymer being selectedfrom the group consisting of polysulfones, polyphenylenes, polyethersulfones, polyimides, polyamide imides, polyarylene ethers,polyphenylene sulfides, polyarylene ether ketones, phenoxy resins,polycarbonates, polyether imides, polyquinoxalines, polyquinolines,polybenzimidazoles, polybenzoxazoles, polybenzothiazoles,polyoxadiazoles, copolymers thereof, and mixtures thereof. Anotherembodiment of the present invention is directed to a process whichcomprises the steps of (a) providing a polymer of the above formula; (b)exposing the polymer to actinic radiation, thereby causing the polymerto become crosslinked or chain extended through thephotosensitivity-imparting groups; and (c) subsequent to step (b),heating the polymer to a temperature sufficient to cause furthercrosslinking or chain extension of the polymer through the thermalsensitivity imparting group, said temperature being at least about 140°C. Yet another embodiment of the present invention is directed to aprocess which comprises the steps of:

(a) depositing a layer comprising the aforementioned polymer onto alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes having terminal ends formed thereon,said polymer being deposited onto the surface having the heatingelements and addressing electrodes thereon;

(b) exposing the layer to actinic radiation in an imagewise pattern suchthat the polymer in exposed areas becomes crosslinked or chain extendedand the polymer in unexposed areas does not become crosslinked or chainextended, wherein the unexposed areas correspond to areas of the lowersubstrate having thereon the heating elements and the terminal ends ofthe addressing electrodes;

(c) removing the polymer from the unexposed areas, thereby formingrecesses in the layer, said recesses exposing the heating elements andthe terminal ends of the addressing electrodes;

(d) subsequent to step (c), heating the crosslinked or chain extendedpolymer to a temperature of at least about 140° C.;

(e) providing an upper substrate with a set of parallel grooves forsubsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

(f) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.

In microelectronics applications, there is a great need for lowdielectric constant, high glass transition temperature, thermallystable, photopatternable polymers for use as interlayer dielectriclayers and as passivation layers which protect microelectronic circuitryPoly(imides) are widely used to satisfy these needs; these materials,however, have disadvantageous characteristics such as relatively highwater sorption and hydrolytic instability. There is thus a need for highperformance polymers which can be effectively photopatterned anddeveloped at high resolution.

One particular application for such materials is the fabrication of inkjet printheads. Ink jet printing systems generally are of two types:continuous stream and drop-on-demand. In continuous stream ink jetsystems, ink is emitted in a continuous stream under pressure through atleast one orifice or nozzle. The stream is perturbed, causing it tobreak up into droplets at a fixed distance from the orifice. At thebreak-up point, the droplets are charged in accordance with digital datasignals and passed through an electrostatic field which adjusts thetrajectory of each droplet in order to direct it to a gutter forrecirculation or a specific location on a recording medium. Indrop-on-demand systems, a droplet is expelled from an orifice directlyto a position on a recording medium in accordance with digital datasignals. A droplet is not formed or expelled unless it is to be placedon the recording medium.

Since drop-on-demand systems require no ink recovery, charging, ordeflection, the system is much simpler than the continuous stream type.There are different types of drop-on-demand ink jet systems. One type ofdrop-on-demand system has as its major components an ink filled channelor passageway having a nozzle on one end and a piezoelectric transducernear the other end to produce pressure pulses. The relatively large sizeof the transducer prevents close spacing of the nozzles, and physicallimitations of the transducer result in low ink drop velocity. Low dropvelocity seriously diminishes tolerances for drop velocity variation anddirectionality, thus impacting the system's ability to produce highquality copies. Drop-on-demand systems which use piezoelectric devicesto expel the droplets also suffer the disadvantage of a slow printingspeed.

The other type of drop-on-demand system is known as thermal ink jet, orbubble jet, and produces high velocity droplets and allows very closespacing of nozzles. The major components of this type of drop-on-demandsystem are an ink filled channel having a nozzle on one end and a heatgenerating resistor near the nozzle. Printing signals representingdigital information originate an electric current pulse in a resistivelayer within each ink passageway near the orifice or nozzle, causing theink in the immediate vicinity to vaporize almost instantaneously andcreate a bubble. The ink at the orifice is forced out as a propelleddroplet as the bubble expands. When the hydrodynamic motion of the inkstops, the process is ready to start all over again. With theintroduction of a droplet ejection system based upon thermally generatedbubbles, commonly referred to as the “bubble jet” system, thedrop-on-demand ink jet printers provide simpler, lower cost devices thantheir continuous stream counterparts, and yet have substantially thesame high speed printing capability.

The operating sequence of the bubble jet system begins with a currentpulse through the resistive layer in the ink filled channel, theresistive layer being in close proximity to the orifice or nozzle forthat channel. Heat is transferred from the resistor to the ink. The inkbecomes superheated far above its normal boiling point, and for waterbased ink, finally reaches the critical temperature for bubble formationor nucleation of around 280° C. Once nucleated, the bubble or watervapor thermally isolates the ink from the heater and no further heat canbe applied to the ink. This bubble expands until all the heat stored inthe ink in excess of the normal boiling point diffuses away or is usedto convert liquid to vapor, which removes heat due to heat ofvaporization. The expansion of the bubble forces a droplet of ink out ofthe nozzle, and once the excess heat is removed, the bubble collapses.At this point, the resistor is no longer being heated because thecurrent pulse has passed and, concurrently with the bubble collapse, thedroplet is propelled at a high rate of speed in a direction towards arecording medium. The surface of the printhead encounters a severecavitational force by the collapse of the bubble, which tends to erodeit. Subsequently, the ink channel refills by capillary action. Thisentire bubble formation and collapse sequence occurs in about 10microseconds. The channel can be refired after 100 to 500 microsecondsminimum dwell time to enable the channel to be refilled and to enablethe dynamic refilling factors to become somewhat dampened. Thermal inkjet equipment and processes are well known and are described in, forexample, U.S. Pat. No. 4,601,777, U.S. Pat. No. 4,251,824, U.S. Pat. No.4,410,899, U.S. Pat. No. 4,412,224, U.S. Pat. No. 4,532,530, and U.S.Pat. No. 4,774,530, the disclosures of each of which are totallyincorporated herein by reference.

The present invention is suitable for ink jet printing processes,including drop-on-demand systems such as thermal ink jet printing,piezoelectric drop-on-demand printing, and the like.

In ink jet printing, a printhead is usually provided having one or moreink-filled channels communicating with an ink supply chamber at one endand having an opening at the opposite end, referred to as a nozzle.These printheads form images on a recording medium such as paper byexpelling droplets of ink from the nozzles onto the recording medium.The ink forms a meniscus at each nozzle prior to being expelled in theform of a droplet. After a droplet is expelled, additional ink surges tothe nozzle to reform the meniscus.

In thermal ink jet printing, a thermal energy generator, usually aresistor, is located in the channels near the nozzles a predetermineddistance therefrom. The resistors are individually addressed with acurrent pulse to momentarily vaporize the ink and form a bubble whichexpels an ink droplet. As the bubble grows, the ink bulges from thenozzle and is contained by the surface tension of the ink as a meniscus.The rapidly expanding vapor bubble pushes the column of ink filling thechannel towards the nozzle. At the end of the current pulse the heaterrapidly cools and the vapor bubble begins to collapse. However, becauseof inertia, most of the column of ink that received an impulse from theexploding bubble continues its forward motion and is ejected from thenozzle as an ink drop. As the bubble begins to collapse, the ink stillin the channel between the nozzle and bubble starts to move towards thecollapsing bubble, causing a volumetric contraction of the ink at thenozzle and resulting in the separation of the bulging ink as a droplet.The acceleration of the ink out of the nozzle while the bubble isgrowing provides the momentum and velocity of the droplet in asubstantially straight line direction towards a recording medium, suchas paper.

Ink jet printheads include an array of nozzles and may, for example, beformed of silicon wafers using orientation dependent etching (ODE)techniques. The use of silicon wafers is advantageous because ODEtechniques can form structures, such as nozzles, on silicon wafers in ahighly precise manner. Moreover, these structures can be fabricatedefficiently at low cost. The resulting nozzles are generally triangularin cross-section. Thermal ink jet printheads made by using theabove-mentioned ODE techniques typically comprise a channel plate whichcontains a plurality of nozzle-defining channels located on a lowersurface thereof bonded to a heater plate having a plurality of resistiveheater elements formed on an upper surface thereof and arranged so thata heater element is located in each channel. The upper surface of theheater plate typically includes an insulative layer which is patternedto form recesses exposing the individual heating elements. Thisinsulative layer is referred to as a “pit layer” and is sandwichedbetween the channel plate and heater plate. For examples of printheadsemploying this construction, see U.S. Pat. No. 4,774,530 and U.S. Pat.No. 4,829,324, the disclosures of each of which are totally incorporatedherein by reference. Additional examples of thermal ink jet printheadsare disclosed in, for example, U.S. Pat. No. 4,835,553, U.S. Pat. No.5,057,853, and U.S. Pat. No. 4,678,529, the disclosures of each of whichare totally incorporated herein by reference.

The photopatternable polymers of the present invention are also suitablefor other photoresist applications, including other microelectronicsapplications, printed circuit boards, lithographic printing processes,interlayer dielectrics, and the like.

U.S. Pat. No. 3,914,194 (Smith), the disclosure of which is totallyincorporated herein by reference, discloses a formaldehyde copolymerresin having dependent unsaturated groups with the repeating unit

wherein R is an aliphatic acyl group derived from saturated acids having2 to 6 carbons, olefinically unsaturated acids having 3 to 20 carbons,or an omega-carboxy-aliphatic acyl group derived from olefinicallyunsaturated dicarboxylic acids having 4 to 12 carbons or mixturesthereof, R₁ is independently hydrogen, an alkyl group of 1 to 10 carbonatoms, or halogen, Z is selected from oxygen, sulfur, the grouprepresented by Z taken with the dotted line represents dibenzofuran anddibenzothiophene moieties, or mixtures thereof, n is a whole numbersufficient to give a weight average molecular weight greater than about500, m is 0 to 2, p and q have an average value of 0 to 1 with theproviso that the total number of p and q groups are sufficient to givegreater than one unsaturated group per resin molecule. These resins areuseful to prepare coatings on various substrates or for pottingelectrical components by mixing with reactive diluents and curing agentsand curing.

“Chloromethylation of Condensation Polymers Containing anoxy-1,4-phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference, discloses the chloromethylation of polymerscontaining oxy-phenylene repeat units to produce film forming resinswith high chemical reactivity. The utility of 1,4-bis(chloromethoxy)butane and 1-chloromethoxy-4-chlorobutane as chloromethylating agentsare also described.

European Patent Application EP-0,698,823-A1 (Fahey et al.), thedisclosure of which is totally incorporated herein by reference,discloses a copolymer of benzophenone and bisphenol A which was shown tohave deep ultraviolet absorption properties. The copolymer was founduseful as an antireflective coating in microlithography applications.Incorporating anthracene into the copolymer backbone enhanced absorptionat 248 nm. The encapper used for the copolymer varied depending on theneeds of the user and was selectable to promote adhesion, stability, andabsorption of different wavelengths.

M. Camps, M. Chatzopoulos, and J. Montheard, “Chloromethyl Styrene:Synthesis, Polymerization, Transformations, Applications,” JMS—Rev.Macromol. Chem. Phys., C22(3), 343-407 (1982-3), the disclosure of whichis totally incorporated herein by reference, discloses processes for thepreparation of chloromethyl-substituted polystyrenes, as well asapplications thereof.

Y. Tabata, S. Tagawa, and M. Washio, “Pulse Radiolysis Studies on theMechanism of the High Sensitivity of Chloromethylated Polystyrene as anElectron Negative Resist,” Lithography, 25(1), 287 (1984), thedisclosure of which is totally incorporated herein by reference,discloses the use of chloromethylated polystyrene in resistapplications.

M. J. Jurek, A. E. Novembre, 1. P. Heyward, R. Gooden, and E.Reichmanis, “Deep UV Photochemistry of Copolymers ofTrimethyl-Silylmethyl Methacrylate and Chloromethylstyrene,” PolymerPreprints, 29(1) (1988), the disclosure of which is totally incorporatedherein by reference, discloses the use of an organosilicon polymer ofchloromethylstyrene for resist applications.

P. M. Hergenrother, B. J. Jensen, and S. J. Havens, “Poly(aryleneethers),” Polymer, 29, 358 (1988), the disclosure of which is totallyincorporated herein by reference, discloses several arylene etherhomopolymers and copolymers prepared by the nucleophilic displacement ofaromatic dihalides with aromatic potassium bisphenates. Polymer glasstransition temperatures ranged from 114 to 310° C. and some weresemicrystalline. Two ethynyl-terminated polyarylene ethers) weresynthesized by reacting hydroxy-terminated oligomers with4-ethynylbenzoyl chloride. Heat induced reaction of the acetylenicgroups provided materials with good solvent resistance. The chemistry,physical, and mechanical properties of the polymers are also disclosed.

S. J. Havens, “Ethynyl-Terminated Polyarylates: Synthesis andCharacterization,” Journal of Polymer Science: Polymer ChemistryEdition, vol. 22, 3011-3025 (1984), the disclosure of which is totallyincorporated herein by reference, discloses hydroxy-terminatedpolyarylates with number average molecular weights of about 2500, 5000,7500, and 10,000 which were synthesized and converted to corresponding4-ethynylbenzoyloxy-terminated polyarylates by reaction with4-ethynylbenzoyl chloride. The terminal ethynyl groups were thermallyreacted to provide chain extension and crosslinking. The cured polymerexhibited higher glass transition temperatures and better solventresistance than a high molecular weight linear polyarylate. Solventresistance was further improved by curing2,2-bis(4-ethynylbenzoyloxy-4′-phenyl)propane, a coreactant, with theethynyl-terminated polymer at concentrations of about 10 percent byweight.

N. H. Hendricks and K. S. Y. Lau, “Flare, a Low Dielectric: Constant,High Tg, Thermally Stable Poly(arylene ether) Dielectric forMicroelectronic Circuit Interconnect Process Integration: Synthesis,Characterization, Thermomechanical Properties, and Thin-Film ProcessingStudies,” Polymer Preprints, 37(1), 150 (1996), the disclosure of whichis totally incorporated herein by reference, discloses non-carbonylcontaining aromatic polyethers such as fluorinated poly(arylene ethers)based on decafluorobiphenyl as a class of intermetal dielectrics forapplications in sub-half micron multilevel interconnects.

J. J. Zupancic, D. C. Blazej, T. C. Baker, and E. A. Dinkel, “StyreneTerminated Resins as Interlevel Dielectrics for Multichip Models,”Polymer Preprints, 32, (2), 178 (1991), the disclosure of which istotally incorporated herein by reference, discloses vinylbenzyl ethersof polyphenols (styrene terminated resins) which were found to bephotochemically and thermally labile, generating highly crosslinkednetworks. The resins were found to yield no volatile by-products duringthe curing process and high glass transition, low dielectric constantcoatings. One of the resins was found to be spin coatable to varyingthickness coatings which could be photodefined, solvent developed, andthen hard baked to yield an interlevel dielectric.

Japanese Patent Kokai JP 04294148-A, the disclosure of which is totallyincorporated herein by reference, discloses a liquid injecting recordinghead containing the cured matter of a photopolymerizable compositioncomprising (1) a graft polymer comprising (A) alkyl methacrylate,acrylonitrile, and/or styrene as the trunk chain and an —OHgroup-containing acryl monomer, (B) amino or alkylamino group-containingacryl monomer, (C) carboxyl group-containing acryl or vinyl monomers,(D) N-vinyl pyrrolidone, vinyl pyridine or its derivatives, and/or (F)an acrylamide as the side chain; (2) a linear polymer containingconstitutional units derived from methyl methacrylate, ethylmethacrylate, isobutyl methacrylate, t-butyl methacrylate, benzylmethacrylate, acrylonitrile, isobornyl methacrylate, tricyclodecaneacrylate, tricyclodecane oxyethyl methacrylate, styrene,dimethylaminoethyl methacrylate, and/or cyclohexyl methacrylate, andconstitutional unit derived from the above compounds (A), (B), (C), (D),(E), or (F) above: (3) an ethylenic unsaturated bond containing monomer;and (4) a photopolymerization initiator which contains (a) an organicperoxide, s-triazine derivative, benzophenone or its derivatives,quinones, N-phenylglycine, and/or alkylarylketones as a radicalgenerator and (b) coumarin dyes, ketocoumarin dyes, cyanine dyes,merocyanine dyes, and/or xanthene dyes as a sensitizer.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 2a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s Containing Vinylbenzyl and Ethynylbenzyl Chain Ends,” V.Percec and B. C. Auman, Makromol. Chem., 185, 1867-1880 (1984), thedisclosure of which is totally incorporated herein by reference,discloses a method for the synthesis of α,ω-bis(vinylbenzyl) aromaticpoly(ether sulfone)s and their transformation intoα,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s. The method entailsa fast and quantitative Williamson etherification of theα,ω-bis(hydroxyphenyl) polysulfone with a mixture of p- andm-chloromethylstyrenes in the presence of tetrabutylammonium hydrogensulfate as phase transfer catalyst, a subsequent bromination, and then adehydrobromination with potassium tert-butoxide. The DSC study of thethermal curing of the α,ω-bis(vinylbenzyl) aromatic poly(ether sulfone)sand α,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s demonstrateshigh thermal reactivity for the styrene-terminated oligomers.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 3a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s and Poly(oxy-2,6-dimethyl-1,4-phenylene) Containing PendentVinyl Groups,” V. Percec and B. C. Auman, Makromol. Chem., 185,2319-2336 (1984), the disclosure of which is totally incorporated hereinby reference, discloses a method for the syntheses of α,ω-benzylaromatic poly(ether sulfone)s (PSU) andpoly(oxy-2,6-dimethyl-1,4-phenylene) (POP) containing pendant vinylgroups. The first step of the synthetic procedure entails thechloromethylation of PSU and POP to provide polymers with chloromethylgroups. POP, containing bromomethyl groups, was obtained by radicalbromination of the methyl groups. Both chloromethylated andbromomethylated starting materials were transformed into theirphosphonium salts, and then subjected to a phase transfer catalyzedWittig reaction to provide polymers with pendant vinyl groups. A PSUwith pendant ethynyl groups was prepared by bromination of the PSUcontaining vinyl groups, followed by a phase transfer catalyzeddehydrobromination. DSC of the thermal curing of the polymers containingpendant vinyl and ethynyl groups showed that the curing reaction is muchfaster for the polymers containing vinyl groups. The resulting networkpolymers are flexible when the starting polymer contains vinyl groups,and very rigid when the starting polymer contains ethynyl groups.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis,” V. Percec and P. L. Rinaldi, Polymer Bulletin, 10, 223(1983), the disclosure of which is totally incorporated herein byreference, discloses the preparation of p- andm-hydroxymethylphenylacetylenes by a two step sequence starting from acommercial mixture of p- and m-chloromethylstyrene, i.e., by thebromination of the vinylic monomer mixture followed by separation of m-and p-brominated derivatives by fractional crystallization, andsimultaneous dehydrobromination and nucleophilic substitution of the —Clwith —OH.

U.S. Pat. No. 4,110,279 (Nelson et al.), the disclosure of which istotally incorporated herein by reference, discloses a polymer derived byheating in the presence of an acid catalyst at between about 65° C. andabout 250° C.: I. a reaction product, a cogeneric mixture of alkoxyfunctional compounds, having average equivalent weights in the range offrom about 220 to about 1200, obtained by heating in the presence of astrong acid at about 50° C. to about 250° C.: (A) a diaryl compoundselected from naphthalene, diphenyl oxide, diphenyl sulfide, theiralkylated or halogenated derivatives, or mixtures thereof, (B)formaldehyde or formaldehyde yielding derivative, (C) water, and (D) ahydroxy aliphatic hydrocarbon compound having at least one free hydroxylgroup and from 1 to 4 carbon atoms, which mixture contains up to 50percent unreacted (A); with II. at least one monomeric phenolic reactantselected from the group

wherein R is selected from the group consisting of hydrogen, alkylradical of 1 to 20 carbon atoms, aryl radical of 6 to 20 carbon atoms,wherein R₁ represents hydrogen, alkyl, or aryl, m represents an integerfrom 1 to 3, o represents an integer from 1 to 5, p represents aninteger from 0 to 3, X represents oxygen, sulfur, or alkylidene, and qrepresents an integer from 0 to 1; and III. optionally an aldehyde oraldehyde-yielding derivative or ketone, for from several minutes toseveral hours. The polymeric materials are liquids or low melting solidswhich are capable of further modification to thermoset resins. Thesepolymers are capable of being thermoset by heating at a temperature offrom about 130° C. to about 260° C. for from several minutes to severalhours in the presence of a formaldehyde-yielding compound. Thesepolymers are also capable of further modification by reacting underbasic conditions with formaldehyde with or without a phenolic compound.The polymers, both base catalyzed resoles and acid catalyzed novolacs,are useful as laminating, molding, film-forming, and adhesive materials.The polymers, both resoles and novolacs, can be epoxidized as well asreacted with a drying oil to produce a varnish resin.

U.S. Pat. No. 3,367,914 (Herbert), the disclosure of which is totallyincorporated herein by reference, discloses thermosetting resinousmaterials having melting points in the range of from 150° C. to 350° C.which are made heating at a temperature of from −10° C. to 100° C. for 5to 30 minutes an aldehyde such as formaldehyde or acetaldehyde with amixture of poly(aminomethyl) diphenyl ethers having an average of fromabout 1.5 to 4.0 aminomethyl groups. After the resins are cured underpressure at or above the melting point, they form adherent tough filmson metal substrates and thus are useful as wire coatings for electricalmagnet wire for high temperature service at 180° C. or higher.

J. S. Amato, S. Karady, M. Sletzinger, and L. M. Weinstock, “A NewPreparation of Chloromethyl Methyl Ether Free of Bis(chloromethyl)Ether,” Synthesis, 970 (1979), the disclosure of which is totallyincorporated herein by reference, discloses the synthesis ofchloromethyl methyl ether by the addition of acetyl chloride to a slightexcess of anhydrous dimethoxymethane containing a catalytic amount ofmethanol at room temperature. The methanol triggers a series ofreactions commencing with formation of hydrogen chloride and thereaction of hydrogen chloride with dimethoxymethane to form chloromethylmethyl ether and methanol in an equilibrium process. After 36 hours, anear-quantitative conversion to an equimolar mixture of chloromethylmethyl ether and methyl acetate is obtained.

A. McKillop, F. A. Madjdabadi, and D. A. Long, “A Simple and InexpensiveProcedure for Chloromethylation of Certain Aromatic Compounds,”Tetrahedron Letters, Vol. 24, No. 18, pp. 1933-1936 (1983), thedisclosure of which is totally incorporated herein by reference,discloses the reaction of a range of aromatic compounds withmethoxyacetyl chloride and aluminum chloride in either nitromethane orcarbon disulfide to result in chloromethylation in good to excellentyield.

E. P. Tepenitsyna, M. I. Farberov, and A. P. Ivanovskii, “Synthesis ofIntermediates for Production of Heat Resistant Polymers(Chloromethylation of Diphenyl Oxide),” Zhurnal Prikladnoi Khimii, Vol.40, No. 11, pp. 2540-2546 (1967), the disclosure of which is totallyincorporated herein by reference, discloses the chloromethylation ofdiphenyl oxide by (1) the action of paraformaldehyde solution in glacialacetic acid saturated with hydrogen chloride, and by (2) the action ofparaformaldehyde solution in concentrated hydrochloric acid.

U.S. Pat. No. 2,125,968 (Theimer), the disclosure of which is totallyincorporated herein by reference, discloses the manufacture of aromaticalcohols by the Friedel-Crafts reaction, in which an alkylene oxide iscondensed with a Friedel-Crafts reactant in the presence of an anhydrousmetal halide.

Copending application U.S. Ser. No. 08/705,914 filed concurrentlyherewith, entitled “Thermal Ink Jet Printhead With Ink Resistant HeatSink Coating,” with the named inventors Ram S. Narang and Timothy J.Fuller, the disclosure of which is totally incorporated herein byreference, discloses a heat sink for a thermal ink jet printhead havingimproved resistance to the corrosive effects of ink by coating thesurface of the heat sink with an ink resistant film formed byelectrophoretically depositing a polymeric material on the heat sinksurface. In one described embodiment, a thermal ink jet printer isformed by bonding together a channel plate and a heater plate. Resistorsand electrical connections are formed in the surface of the heaterplate. The heater plate is bonded to a heat sink comprising a zincsubstrate having an electrophoretically deposited polymeric filmcoating. The film coating provides resistance to the corrosion of higherpH inks. In another embodiment, the coating has conductive fillersdispersed therethrough to enhance the thermal conductivity of the heatsink. In one embodiment, the polymeric material is selected from thegroup consisting of polyethersulfones, polysulfones, polyamides,polyimides, polyamide-imides, epoxy resins, polyetherimides, polyaryleneether ketones, chloromethylated polyarylene ether ketones, acryloylatedpolyarylene ether ketones, polystyrene and mixtures thereof.

Copending application U.S. Ser. No. 08/703,138, filed concurrentlyherewith, entitled “Method for Applying an Adhesive Layer to a SubstrateSurface,” with the named inventors Ram S. Narang, Stephen F. Pond, andTimothy J. Fuller, now U.S. Pat. No. 5,843,249, the disclosure of whichis totally incorporated herein by reference, discloses a method foruniformly coating portions of the surface of a substrate which is to bebonded to another substrate. In a described embodiment, the twosubstrates are channel plates and heater plates which, when bondedtogether, form a thermal ink jet printhead. The adhesive layer iselectrophoretically deposited over a conductive pattern which has beenformed on the binding substrate surface. The conductive pattern forms anelectrode and is placed in an electrophoretic bath comprising acolloidal emulsion of a preselected polymer adhesive. The otherelectrode is a metal container in which the solution is placed or aconductive mesh placed within the contoiner. The electrodes areconnected across a voltage source and a field is applied. The substrateis placed in contact with the solution, and a small current flow iscarefully controlled to create an extremely uniform thin deposition ofcharged adhesive micelles on the surface of the conductive pattern. Thesubstrate is then removed and can be bonded to a second substrate andcured. In one embodiment, the polymer adhesive is selected from thegroup consisting of polyamides, polyimides, polyamide-imides, epoxyresins, polyetherimides, polysulfones, polyether sulfones, polyaryleneether ketones, polystyrenes, chloromethylated polyarylene ether ketones,acryloylated plyarylene ether ketones, and mixtures thereof.

Copending application U.S. Ser. No. 08/697,750, filed concurrentlyherewith, entitled “Electrophoretically Deposited Coating For the FrontFace of an Ink Jet Printhead,” with the named inventors Ram S. Narang,Stephen F. Pond, and Timothy J. Fuller, the disclosure of which istotally incorporated herein by reference, discloses an electrophoreticdeposition technique for improving the hydrophobicity of a metalsurface, in one embodiment, the front face of a thermal ink jetprinthead. For this example, a thin metal layer is first deposited onthe front face. The front face is then lowered into a colloidal bathformed by a fluorocarbon-doped organic system dissolved in a solvent andthen dispersed in a non-solvent. An electric field is created and asmall amount of current through the bath causes negatively chargedparticles to be deposited on the surface of the metal coating. Bycontrolling the deposition time and current strength, a very uniformcoating of the fluorocarbon compound is formed on the metal coating. Theelectrophoretic coating process is conducted at room temperature andenables a precisely controlled deposition which is limited only to thefront face without intrusion into the front face orifices. In oneembodiment, the organic compound is selected from the group consistingof polyimides, polyamides, polyamide-imides, polysulfones, polyaryleneether ketones, polyethersulfones, polytetrafluoroethylenes,polyvinylidene fluorides, polyhexafluoro-propylenes, epoxies,polypentafluorostyrenes, polystyrenes, copolymers thereof, terpolymersthereof, and mixtures thereof.

Copending application U.S. Ser. No. 08/705,916 filed concurrentlyherewith, entitled “Stabilized Graphite Substrates,” with the namedinventors Gary A. Kneezel, Ram S. Narang, Timothy J. Fuller, and PeterJ. John, now U.S. Pat. 5,939,206, the disclosure of which is totallyincorporated herein by reference, discloses an apparatus which comprisesat least one semiconductor chip mounted on a substrate, said substratecomprising a graphite member having electrophoretically depositedthereon a coating of a polymeric material. In one embodiment, thesemiconductor chips are thermal ink jet printhead subunits. In oneembodiment, the polymeric material is of the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,10 such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units.

Copending application U.S. Ser. No. 08/705,375, filed concurrentlyherewith, entitled “Improved Curable Compositions,” with the namedinventors Timothy J. Fuller, Ram S. Narang, Thomas W. Smith, David J.Luca, and Ralph A. Mosher, now U.S. Pat. No. 5,994,425, the disclosureof which is totally incorporated herein by reference, discloses animproved composition comprising a photopatternable polymer containing atleast some monomer repeat units with photosensitivity-impartingsubstituents, said photopatternable polymer being of the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units. Also disclosed is a process for preparing athermal ink jet printhead with the aforementioned polymer and a thermalink jet printhead containing therein a layer of a crosslinked or chainextended polymer of the above formula.

Copending application U.S. Ser. No. 08/705,365, filed concurrentlyherewith, entitled “Hydroxyalkylated High Performance Curable Polymers,”with the named inventors Ram S. Narang and Timothy J. Fuller, now U.S.Pat. No. 5,849,809, the disclosure of which is totally incorporatedherein by reference, discloses a composition which comprises (a) apolymer containing at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are hydroxyalkyl groups; (b) at least one member selectedfrom the group consisting of photoinitiators and sensitizers; and (c) anoptional solvent. Also disclosed are processes for preparing the abovepolymers and methods of preparing thermal ink jet printheads containingthe above polymers.

Copending application U.S. Ser. No. 08/697,761, filed concurrentlyherewith, entitled “Process for Direct Substitution of High PerformancePolymers with Unsaturated Ester Groups,” with the named inventorsTimothy J. Fuller, Ram S. Narang, Thomas W. Smith, David J. Luca, andRaymond K. Crandall, now U.S. Pat. No. 5,889,077, the disclosure ofwhich is totally incorporated herein by reference, discloses a processwhich comprises reacting a polymer of the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with (i) a formaldehyde source, and (ii) anunsaturated acid in the presence of an acid catalyst, thereby forming acurable polymer with unsaturated ester groups. Also disclosed is aprocess for preparing an ink jet printhead with the above polymer.

Copending application U.S. Ser. No. 08/705,463, filed concurrentlyherewith, entitled “Process for Haloalkylation of High PerformancePolymers,” with the named inventors Timothy J. Fuller, Ram S. Narang,Thomas W. Smith, David J. Luca, and Raymond K. Crandall, now U.S. Pat.No. 5,739,254,the disclosure of which is totally incorporated herein byreference, discloses a process which comprises reacting a polymer of thegeneral formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with an acetyl halide and dimethoxymethane inthe presence of a halogen-containing Lewis acid catalyst and methanol,thereby forming a haloalkylated polymer. In a specific embodiment, thehaloalkylated polymer is then reacted further to replace at least someof the haloalkyl groups with photosensitivity-imparting groups. Alsodisclosed is a process for preparing a thermal ink jet printhead withthe aforementioned polymer.

Copending application U.S. Ser. No. 08/705,479, filed concurrentlyherewith, entitled “Processes for Substituting Haloalkylated PolymersWith Unsaturated Ester, Ether, and Alkylcarboxymethylene Groups,” withthe named inventors Timothy J. Fuller, Ram S. Narang, Thomas W. Smith,David J. Luca, and Raymond K. Crandall, now U.S. Pat. No. 5,761,809, thedisclosure of which is totally incorporated herein by reference,discloses a process which comprises reacting a haloalkylated aromaticpolymer with a material selected from the group consisting ofunsaturated ester salts, alkoxide salts, alkylcarboxylate salts, andmixtures thereof, thereby forming a curable polymer having functionalgroups corresponding to the selected salt. Another embodiment of theinvention is directed to a process for preparing an ink jet printheadwith the curable polymer thus prepared.

Copending application U.S. Ser. No. 08/705,376, filed concurrentlyherewith, entitled “Blends Containing Curable Polymers,” with the namedinventors Ram S. Narang and Timothy J. Fuller, now U.S. Pat. No.5,958,995, the disclosure of which is totally incorporated herein byreference, discloses a composition which comprises a mixture of (A) afirst component comprising a polymer, at least some of the monomerrepeat units of which have at least one photosensitivity-imparting groupthereon, said polymer having a first degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture is from about 10,000 to about50,000; and wherein the third or fifth degree ofphotosensitivity-imparting group substitution is from about 0.25 toabout 2 milliequivalents of photosensitivity-imparting groups per gramof mixture. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned composition.

Copending application U.S. Ser. No. 08/705,372, filed concurrentlyherewith, entitled “High Performance Curable Polymers and Processes forthe Preparation Thereof,” with the named inventors Ram S. Narang andTimothy J. Fuller, now U.S. Pat. No. 5,945,253, the disclosure of whichis totally incorporated herein by reference, discloses a compositionwhich comprises a polymer containing at least some monomer repeat unitswith photosensitivity-imparting substituents which enable crosslinkingor chain extension of the polymer upon exposure to actinic radiation,said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are allyl ether groups, epoxy groups, or mixtures thereof.Also disclosed are a process for preparing a thermal ink jet printheadcontaining the aforementioned polymers and processes for preparing theaforementioned polymers.

Copending application U.S. Ser. No. 08/705,490, filed concurrentlyherewith, entitled “Halomethylated High Performance Curable Polymers,”with the named inventors Ram S. Narang and Timothy J. Fuller, now U.S.Pat. No. 5,963,963, the disclosure of which is totally incorporatedherein by reference, discloses a process which comprises the steps of(a) providing a polymer containing at least some monomer repeat unitswith halomethyl group substituents which enable crosslinking or chainextension of the polymer upon exposure to a radiation source which iselectron beam radiation, x-ray radiation, or deep ultraviolet radiation,said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, and (b) causing the polymer to becomecrosslinked or chain extended through the photosensitivity-impartinggroups. Also disclosed is a process for preparing a thermal ink jetprinthead by the aforementioned curing process.

Copending application U.S. Ser. No. 08/697,760, filed concurrentlyherewith, entitled “Aqueous Developable High Performance CurablePolymers,” with the named inventors Ram S. Narang and Timothy J. Fuller,now U.S. Pat. No. 6,007,877, . the disclosure of which is totallyincorporated herein by reference, discloses a composition whichcomprises a polymer containing at least some monomer repeat units withwater-solubility-imparting substituents and at least some monomer repeatunits with photosensitivity-imparting substituents which enablecrosslinking or chain extension of the polymer upon exposure to actinicradiation, said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

 or mixtures thereof, and n is an integer representing the number ofrepeating monomer units. In one embodiment, a single functional groupimparts both photosensitivity and water solubility to the polymer. Inanother embodiment, a first functional group imparts photosensitivity tothe polymer and a second functional group imparts water solubility tothe polymer. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned polymers.

While known compositions and processes are suitable for their intendedpurposes, a need remains for improved materials suitable formicroelectronics applications. A need also remains for improved ink jetprintheads. Further, there is a need for photopatternable polymericmaterials which are heat stable, electrically insulating, andmechanically robust. Additionally, there is a need for photopatternablepolymeric materials which are chemically inert with respect to thematerials that might be employed in ink jet ink compositions. There isalso a need for photopatternable polymeric materials which exhibit lowshrinkage during post-cure steps in microelectronic device fabricationprocesses. In addition, a need remains for photopatternable polymericmaterials which exhibit a relatively long shelf life. Further, there isa need for photopatternable polymeric materials which can be patternedwith relatively low photo-exposure energies. Additionally, a needremains for photopatternable polymeric materials which, in the curedform, exhibit good solvent resistance. There is also a need forphotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips. In addition, thereremains a need for photopatternable polymeric materials which haverelatively low dielectric constants. Further, there is a need forphotopatternable polymeric materials which exhibit reduced watersorption. Additionally, a need remains for photopatternable polymericmaterials which exhibit improved hydrolytic stability, especially uponexposure to alkaline solutions. A need also remains for photopatternablepolymeric materials which are stable at high temperatures, typicallygreater than about 150° C. A need further remains for photopatternablepolymeric materials which have glass transition temperatures in excessof 150° C. and are stable at high temperatures, typically greater thanabout 250° C. There is also a need for photopatternable polymericmaterials which either have high glass transition temperatures in excessof about 150C. subsequent to post-exposure curing or are sufficientlycrosslinked after post-exposure curing that there are no low temperaturephase transitions subsequent to photoexposure. Further, a need remainsfor photopatternable polymeric materials with low coefficients ofthermal expansion. There is a need for polymers which are thermallystable, patternable as thick films of about 30 microns or more, have lowdielectric constants, are low in water absorption, have low coefficientsof expansion, have desirable mechanical and adhesive characteristics,and are generally desirable for interlayer dielectric applications,including those at high temperatures, which are also photopatternable.There is also a need for photoresist compositions with good to excellentprocessing characteristics.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide polymeric materialswith the above noted advantages.

It is another object of the present invention to provide improvedmaterials suitable for microelectronics applications.

It is yet another object of the present invention to provide improvedink jet printheads.

It is still another object of the present invention to providephotopatternable polymeric materials which are heat stable, electricallyinsulating, and mechanically robust.

Another object of the present invention is to provide photopatternablepolymeric materials which are chemically inert with respect to thematerials that might be employed in ink jet ink compositions.

Yet another object of the present invention is to providephotopatternable polymeric materials which exhibit low shrinkage duringpost-cure steps in microelectronic device fabrication processes.

Still another object of the present invention is to providephotopatternable polymeric materials which exhibit a relatively longshelf life.

It is another object of the present invention to providephotopatternable polymeric materials which can be patterned withrelatively low photo-exposure energies.

It is yet another object of the present invention to providephotopatternable polymeric materials which, in the cured form, exhibitgood solvent resistance.

It is still another object of the present invention to providephotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips.

Another object of the present invention is to provide photopatternablepolymeric materials which have relatively low dielectric constants.

Yet another object of the present invention is to providephotopatternable polymeric materials which exhibit reduced watersorption.

Still another object of the present invention is to providephotopatternable polymeric materials which exhibit improved hydrolyticstability, especially upon exposure to alkaline solutions.

It is another object of the present invention to providephotopatternable polymeric materials which are stable at hightemperatures, typically greater than about 150° C.

It is another object of the present invention to providephotopatternable polymeric materials which have glass transitiontemperatures in excess of 150° C. and are stable at high temperatures,typically greater than about 250° C.

It is yet another object of the present invention to providephotopatternable polymeric materials which either have high glasstransition temperatures in excess of about 150C subsequent topost-exposure curing or are sufficiently crosslinked after post-exposurecuring that there are no low temperature phase transitions subsequent tophotoexposure.

It is still another object of the present invention to providephotopatternable polymeric materials with low coefficients of thermalexpansion.

Another object of the present invention is to provide polymers which arethermally stable, patternable as thick films of about 30 microns ormore, have low dielectric constants, are low in water absorption, havelow coefficients of expansion, have desirable mechanical and adhesivecharacteristics, and are generally desirable for interlayer dielectricapplications, including those at high temperatures, which are alsophotopatternable.

Yet another object of the present invention is to provide photoresistcompositions with good to excellent processing characteristics.

These and other objects of the present invention (or specificembodiments thereof) can be achieved by providing a compositioncomprising a polymer with a weight average molecular weight of fromabout 1,000 to about 100,000, said polymer containing at least somemonomer repeat units with a first, photosensitivity-impartingsubstituent which enables crosslinking or chain extension of the polymerupon exposure to actinic radiation, said polymer also containing asecond, thermal sensitivity-imparting substituent which enables furthercrosslinking or chain extension of the polymer upon exposure totemperatures of about 140° C. and higher, wherein the first substituentis not the same as the second substituent, said polymer being selectedfrom the group consisting of polysulfones, polyphenylenes, polyethersulfones, polyimides, polyamide imides, polyarylene ethers,polyphenylene sulfides, polyarylene ether ketones, phenoxy resins,polycarbonates, polyether imides, polyquinoxalines, polyquinolines,polybenzimidazoles, polybenzoxazoles, polybenzothiazoles,polyoxadiazoles, copolymers thereof, and mixtures thereof. Anotherembodiment of the present invention is directed to a process whichcomprises the steps of (a) providing a polymer of the above formula; (b)exposing the polymer to actinic radiation, thereby causing the polymerto become crosslinked or chain extended through thephotosensitivity-imparting groups; and (c) subsequent to step (b),heating the polymer to a temperature sufficient to cause furthercrosslinking or chain extension of the polymer through the thermalsensitivity imparting group, said temperature being at least about 140°C. Yet another embodiment of the present invention is directed to aprocess which comprises the steps of:

(a) depositing a layer comprising the aforementioned polymer onto alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes having terminal ends formed thereon,said polymer being deposited onto the surface having the heatingelements and addressing electrodes thereon;

(b) exposing the layer to actinic radiation in an imagewise pattern suchthat the polymer in exposed areas becomes crosslinked or chain extendedand the polymer in unexposed areas does not become crosslinked or chainextended, wherein the unexposed areas correspond to areas of the lowersubstrate having thereon the heating elements and the terminal ends ofthe addressing electrodes;

(c) removing the polymer from the unexposed areas, thereby formingrecesses in the layer, said recesses exposing the heating elements andthe terminal ends of the addressing electrodes;

(d) subsequent to step (c), heating the crosslinked or chain extendedpolymer to a temperature of at least about 140° C.;

(e) providing an upper substrate with a set of parallel grooves forsubsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

(f) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged schematic isometric view of an example of aprinthead mounted on a daughter board showing the droplet emittingnozzles.

FIG. 2 is an enlarged cross-sectional view of FIG. 1 as viewed along theline 2—2 thereof and showing the electrode passivation and ink flow pathbetween the manifold and the ink channels.

FIG. 3 is an enlarged cross-sectional view of an alternate embodiment ofthe printhead in FIG. 1 as viewed along the line 2—2 thereof.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a composition comprising a polymerwith a weight average molecular weight of from about 1,000 to about100,000, said polymer containing at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer also containing at least one thermal sensitivity-imparting groupwhich enables further crosslinking or chain extension of the polymerupon exposure to heat, said polymer being selected from the groupconsisting of polysulfones, polyphenylenes, polyether sulfones,polyimides, polyamide imides, polyarylene ethers, polyphenylenesulfides, polyarylene ether ketones, phenoxy resins, polycarbonates,polyether imides, polyquinoxalines, polyquinolines, polybenzimidazoles,polybenzoxazoles, polybenzothiazoles, polyoxadiazoles, copolymersthereof, and mixtures thereof.

The polymers of the present invention are generally selected from theclass of high performance polymers, which tend to be stable at hightemperatures of, for example, greater than about 250° C., highlyaromatic, and exhibit little or no flowing at temperatures in excess ofabout 150° C. High performance polymers are often processed in specialsolvents or at temperatures above those at which their use is intended,and are useful for high temperature structural and adhesiveapplications. While most high performance polymers are thermoplastic,many have glass transition temperatures in excess of about 200° C. andsome, such as phenolics, tend to be thermosetting. Examples of highperformance polymers suitable for the present invention includepolysulfones, such as those of the formulae

wherein R is an alkyl group, preferably with from 1 to about 12 carbonatoms, a substituted alkyl group, an aryl group, preferably with from 6to about 24 carbon atoms, a substituted aryl group, an arylalkyl group,preferably with from 7 to about 36 carbon atoms, or a substitutedarylalkyl group, and n is an integer representing the number ofrepeating monomer units, polyphenylenes, such as those of the formula

wherein n is an integer representing the number of repeating monomerunits, polyether sulfones, such as those of the formulae

wherein R is an alkyl group, preferably with from 1 to about 12 carbonatoms, a substituted alkyl group, an aryl group, preferably with from 6to about 24 carbon atoms, a substituted aryl group, an arylalkyl group,preferably with from 7 to about 36 carbon atoms, or a substitutedarylalkyl group, n is an integer representing the number of repeatingmonomer units, and B is

wherein v is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein z is an integer of from 2 to about 20, and preferably from 2 toabout 10,

wherein u is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein w is an integer of from 1 to about 20, and preferably from 1 toabout 10,

other similar bisphenol derivatives, or mixtures thereof, polyimides,such as those of the formulae

wherein n is an integer representing the number of repeating monomerunits and R is selected from

wherein v is an integer of from 1 to about 20, and preferably from 1 toabout 10,

or mixtures thereof, polyamide-imides, such as those of the formulae

wherein R is as defined above for polyimides and n is an integerrepresenting the number of repeating monomer units, polyarylene ethers,such as those of the formulae

wherein B is as defined above for polyether sulfones and n is an integerrepresenting the number of repeating monomer units, polyphenylenesulfides, such as those of the formulae

wherein B is as defined above for polyether sulfones, X is either anoxygen atom or a sulfur atom, and n is an integer representing thenumber of repeating monomer units, polyarylene ether ketones, such asthose of the formulae

wherein R represents an alkyl group, preferably with from 1 to about 12carbon atoms, a substituted alkyl group, an aryl group, preferably withfrom 6 to about 24 carbon atoms, a substituted aryl group, an arylalkylgroup, preferably with from 7 to about 36 carbon atoms, or a substitutedarylalkyl group, Ar represents an aryl group, preferably with from 6 toabout 24 carbon atoms, a substituted aryl group, an arylalkyl group,preferably with from 7 to about 36 carbon atoms, or a substitutedarylalkyl group, B is as defined above for polyether sulfones, and n isan integer representing the number of repeating monomer units, phenoxyresins, such as those of the formula

wherein B is as defined above for polyether sulfones and n is an integerrepresenting the number of repeating monomer units, polycarbonates, suchas those of the formula

wherein B is as defined above for polyether sulfones and n is an integerrepresenting the number of repeating monomer units, polyether imides,such as those of the formulae

wherein R is as defined above for polyimides, B is as defined above forpolyether sulfones, and n is an integer representing the number ofrepeating monomer units, polyquinoxalines, including those of theformulae

wherein m is an integer of 0 or 1, Y is

and n is an integer representing the number of repeating monomer units,polyquinolines, including those of the formulae

wherein n is an integer representing the number of repeating monomerunits, polybenzimidazoles, including those of the formulae

wherein n is an integer representing the number of repeating monomerunits, polybenzoxazoles, including those of the formula

wherein n is an integer representing the number of repeating monomerunits, polybenzothiazoles, including those of the formula

wherein n is an integer representing the number of repeating monomerunits, polyoxadiazoles, including those of the formula

wherein n is an integer representing the number of repeating monomerunits, and the like, as well as copolymers thereof and mixtures thereof.Examples of substituents on the substituted alkyl, aryl, and arylalkylgroups include (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein two or more substituents can bejoined together to form a ring. Any of the phenyl groups and B groupsshown in the above general formulae can also bear one or more of any ofthe above substituents as well as alkyl groups, preferably with from 1to about 12 carbon atoms, substituted alkyl groups, aryl groups,preferably with from 6 to about 24 carbon atoms, substituted alkylgroups, arylalkyl groups, preferably with from 7 to about 26 carbonatoms, substituted arylalkyl groups, or the like, wherein two or moresubstituents can be joined together to form a ring.

In one preferred embodiment, the photopatternable polymer is of thefollowing formula:

wherein Y and Z each, independently of the others, can be (but are notlimited to) alkyl groups, including saturated, unsaturated, and cyclicalkyl groups, preferably with from 1 to about 15 carbon atoms,substituted alkyl groups, including saturated, unsaturated, and cyclicsubstituted alkyl groups, preferably with from 1 to about 15 carbonatoms, aryl groups, preferably with from 6 to about 24 carbon atoms,substituted aryl groups, preferably with from 6 to about 24 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, oxygen atoms (—O—), sulfur atoms (—S—), carbonyl groups(—CO—), sulfone groups (—SO₂—), amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, thiocarbonyl groups, sulfate groups, sulfonate groups,sulfide groups, sulfoxide groups, phosphine groups, phosphonium groups,phosphate groups, mercapto groups, nitroso groups, acyl groups, acidanhydride groups, azide groups, and the like, wherein the substituentson the substituted alkyl groups, substituted aryl groups, andsubstituted arylalkyl groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein two ormore substituents can be joined together to form a ring, m and n each,independently of the other, are integers of from 0 to about 2, Rrepresents one or more optional substituents and can be (but is notlimited to) alkyl groups, including saturated, unsaturated, and cyclicalkyl groups, preferably with from 1 to about 30 carbon atoms,substituted alkyl groups, including saturated, unsaturated, and cyclicsubstituted alkyl groups, preferably with from 1 to about 30 carbonatoms, aryl groups, preferably with from 6 to about 20 carbon atoms,substituted aryl groups, preferably with from 6 to about 20 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, hydroxy groups, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, aldehydegroups, ketone groups, ester groups, amide groups, carboxylic acidgroups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonategroups, sulfide groups, sulfoxide groups, phosphine groups, phosphoniumgroups, phosphate groups, cyano groups, nitile groups, mercapto groups,nitroso groups, halogen atoms, nitro groups, sulfone groups, acylgroups, acid anhydride groups, azide groups, mixtures thereof, and thelike, wherein the substituents on the substituted alkyl groups,substituted aryl groups, and substituted arylalkyl groups can be (butare not limited to) hydroxy groups, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, aldehydegroups, ketone groups, ester groups, amide groups, carboxylic acidgroups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonategroups, sulfide groups, sulfoxide groups, phosphine groups, phosphoniumgroups, phosphate groups, cyano groups, nitrile groups, mercapto groups,nitroso groups, halogen atoms, nitro groups, sulfone groups, acylgroups, acid anhydride groups, azide groups, mixtures thereof, and thelike, wherein two or more substituents can be joined together to form aring, a and b are each integers of 0, 1, 2, 3, or 4, provided that b isequal to at least 1 in at least some of the monomer repeat units of thepolymer, the sum of a+b is from 0 to 4, and x is an integer representingthe number of repeating monomer units. Typically, x is such that theweight average molecular weight of the material is from about 1,000 toabout 100,000, preferably from about 1,000 to about 65,000, morepreferably from about 3,000 to about 40,000, even more preferably fromabout 10,000 to about 40,000, and most preferably from about 15,000 toabout 25,000, although the value can be outside these ranges. The valueof x will depend on the molecular weight of the monomers, and preferredvalues for x are smaller for larger monomers than they are for smallermonomers. For example, when the polymer is a polystyrene, preferredvalues of x are from about 5 to about 330, although the value can beoutside this range. When the polymer is a polyarylene ether ketone,preferably, x is an integer of from about 5 to about 70, and morepreferably from about 8 to about 50, although the value of n can beoutside these ranges.

One additional example of a suitable polymer for the present inventionis of the formula

wherein x is an integer representing the number of repeating monomerunits, and preferably is from about 5 to about 330, although the valuecan be outside this range. Polymers of these general formulae, includingthose having chloromethyl substituents thereon, can be made by knownmethods, such as those set forth in, for example, S. Imamura et al.,“High Performance Electron Negative Resist, ChloromethylatedPolystyrene: A Study on Molecular Parameters,” J. of Applied PolymerScience, Vol. 27, p. 937 (1982); S. Imamura, “ChloromethylatedPolystyrene as a Dry Etching-Resistant Negative Resist for SubmicronTechnology,” J. Electrochem. Soc.: Solid-state Science and Technology,Vol. 126, no. 9, p. 1628 (1979); and M. E. Wright et al., “DetailsConcerning the Chloromethylation of Soluble High Molecular WeightPolystyrene Using Dimethoxymethane, Thionyl Chloride, and a Lewis Acid:A Full Analysis,” Macromolecules, Vol.1991, no. 24, p. 5879 (1991), thedisclosures of each of which are totally incorporated herein byreference.

In another preferred embodiment, the photopatternable polymer is of thefollowing formula:

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein z is an integer of from 2 to about 20, and preferably from 2 toabout 10,

wherein u is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein w is an integer of from 1 to about 20, and preferably from 1 toabout 10,

other similar bisphenol derivatives, or mixtures thereof, and n is aninteger representing the number of repeating monomer units. The value ofn is such that the weight average molecular weight of the materialtypically is from about 1,000 to about 100,000, preferably from about1,000 to about 65,000, more preferably from about 1,000 to about 40,000,and even more preferably from about 3,000 to about 25,000, although theweight average molecular weight can be outside these ranges. Preferably,n is an integer of from about 2 to about 70, more preferably from about5 to about 70, and even more preferably from about 8 to about 50,although the value of n can be outside these ranges. The phenyl groupsand the A and/or B groups may also be substituted, although the presenceof two or more substituents on the B group ortho to the oxygen groupscan render substitution difficult. Substituents can be present on thepolymer either prior to or subsequent to the placement ofphotosensitivity-imparting functional groups thereon. Substituents canalso be placed on the polymer during the process of placement ofphotosensitivity-imparting functional groups thereon. Examples ofsuitable substituents include (but are not limited to) alkyl groups,including saturated, unsaturated, and cyclic alkyl groups, preferablywith from 1 to about 6 carbon atoms, substituted alkyl groups, includingsaturated, unsaturated, and cyclic substituted alkyl groups, preferablywith from 1 to about 6 carbon atoms, aryl groups, preferably with from 6to about 24 carbon atoms, substituted aryl groups, preferably with from6 to about 24 carbon atoms, arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyl groups, preferably withfrom 7 to about 30 carbon atoms, alkoxy groups, preferably with from 1to about 6 carbon atoms, substituted alkoxy groups, preferably with from1 to about 6 carbon atoms, aryloxy groups, preferably with from 6 toabout 24 carbon atoms, substituted aryloxy groups, preferably with from6 to about 24 carbon atoms, arylalkyloxy groups, preferably with from 7to about 30 carbon atoms, substituted arylalkyloxy groups, preferablywith from 7 to about 30 carbon atoms, hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, ester groups, amide groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, mercaptogroups, nitroso groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, and the like, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein two ormore substituents can be joined together to form a ring. Processes forthe preparation of these materials are known, and disclosed in, forexample, P. M. Hergenrother, J. Macromol. Sci. Rev. Macromol. Chem., C19(1), 1-34 (1980); P. M. Hergenrother, B. J. Jensen, and S. J. Havens,Polymer, 29, 358 (1988): B. J. Jensen and P. M. Hergenrother, “HighPerformance Polymers,” Vol. 1, No. 1) page 31 (1989), “Effect ofMolecular Weight on Poly(arylene ether ketone) Properties”; V. Percecand B. C. Auman, Makromol. Chem. 185, 2319 (1984); “High MolecularWeight Polymers by Nickel Coupling of Aryl Polychlorides,” I. Colon, G.T. Kwaiatkowski, J. of Polymer Science, Part A, Polymer Chemistry, 28,367 (1990); M. Ueda and T. Ito, Polymer J., 23 (4), 297 (1991);“Ethynyl-Terminated Polyarylates: Synthesis and Characterization,” S. J.Havens and P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 22, 3011 (1984); “Ethynyl-Terminated Polysulfones: Synthesisand Characterization,” P. M. Hergenrother, J. of Polymer Science:Polymer Chemistry Edition, 20, 3131 (1982); K. E. Dukes, M. D. Forbes,A. S. Jeevarajan, A. M. Belu, J. M. DeDimone, R. W. Linton, and V. V.Sheares, Macromolecules, 29, 3081 (1996); G. Hougham, G. Tesoro, and J.Shaw, Polym. Mater. Sci. Eng., 61, 369 (1989); V. Percec and B. C.Auman, Makromol. Chem, 185, 617 (1984); “Synthesis and characterizationof New Fluorescent Poly(arylene ethers),” S. Matsuo, N. Yakoh, S. Chino,M. Mitani, and S. Tagami, Journal of Polymer Science: Part A: PolymerChemistry, 32, 1071 (1994); “Synthesis of a Novel Naphthalene-BasedPoly(arylene ether ketone) with High Solubility and Thermal Stability,”Mami Ohno, Toshikazu Takata, and Takeshi Endo, Macromolecules, 27, 3447(1994); “Synthesis and Characterization of New Aromatic Poly(etherketones),” F. W. Mercer, M. T. Mckenzie, G. Merlino, and M. M. Fone, J.of Applied Polymer Science, 56, 1397 (1995); H. C. Zhang, T. L. Chen, Y.G. Yuan, Chinese Patent CN 85108751 (1991); “Static and laser lightscattering study of novel thermoplastics. 1. Phenolphthalein poly(arylether ketone),” C. Wu, S. Bo, M. Siddiq, G. Yang and T. Chen,Macromolecules, 29, 2989 (1996); “Synthesis of t-Butyl-SubstitutedPoly(ether ketone) by Nickel-Catalyzed Coupling Polymerization ofAromatic Dichloride”, M. Ueda, Y. Seino, Y. Haneda, M. Yoneda, and J.-I.Sugiyama, Journal of Polymer Science: Part A: Polymer Chemistry, 32, 675(1994); “Reaction Mechanisms: Comb-Like Polymers and Graft Copolymersfrom Macromers 2. Synthesis, Characterzation and Homopolymerization of aStyrene Macromer of Poly(2,6-dimethyl-1,4-phenylene Oxide),” V. Percec,P. L. Rinaldi, and B. C. Auman, Polymer Bulletin, 10, 397 (1983);Handbook of Polymer Synthesis Part A, Hans R. Kricheldorf, ed., MarcelDekker, Inc., New York-Basel-Hong Kong (1992); and “Introduction ofCarboxyl Groups into Crosslinked Polystyrene,” C. R. Harrison, P. Hodge,J. Kemp, and G. M. Perry, Die Makromolekulare Chemie, 176, 267 (1975),the disclosures of each of which are totally incorporated herein byreference. Further background on high performance polymers is disclosedin, for example, U.S. Pat. No. 2,822,351; U.S. Pat. No. 3,065,205;British Patent 1,060,546; British Patent 971,227; British Patent1,078,234; U.S. Pat. No. 4,175,175; N. Yoda and H. Hiramoto, J.Macromol. Sci.-Chem., A21(13 & 14) pp. 1641 (1984) (Toray Industries,Inc., Otsu, Japan; B. Sillion and L. Verdet, “Polyimides and otherHigh-Temperature polymers”, edited by M. J. M. Abadie and B. Sillion,Elsevier Science Publishers B.V. (Amsterdam 1991); “Polyimides withAlicyclic Diamines. II. Hydrogen Abstraction and PhotocrosslinkingReactions of Benzophenone Type Polyimides,” Q. Jin, T. Yamashita, and K.Horie, J. of Polymer Science: Part A: Polymer Chemistry, 32, 503 (1994);Probimide™ 300, product bulletin, Ciba-Geigy Microelectronics Chemicals,“Photosensitive Polyimide System”; High Performance Polymers andComposites, J. I. Kroschwitz (ed.), John Wiley & Sons (New York 1991);and T. E. Atwood, D. A. Barr, T. A. King, B. Newton, and B. J. Rose,Polymer, 29, 358 (1988), the disclosures of each of which are totallyincorporated herein by reference.

The photopatternable polymers of the present invention contain in atleast some of the monomer repeat units thereofphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation.Radiation which activates crosslinking or chain extension can be of anydesired source and any desired wavelength, including (but not limitedto) visible light, infrared light, ultraviolet light, electron beamradiation, x-ray radiation, or the like. Examples of suitablephotosensitivity imparting groups include unsaturated ester groups, suchas acryloyl groups, methacryloyl groups, cinnamoyl groups, crotonoylgroups, ethacryloyl groups, oleoyl groups, linoleoyl groups, maleoylgroups, fumaroyl groups, itaconoyl groups, citraconoyl groups,phenylmaleoyl groups, esters of 3-hexene-1,6-dicarboxylic acid, and thelike. Also suitable are alkylcarboxymethylene and ether groups. Undercertain conditions, such as imaging with electron beam, deepultraviolet, or x-ray radiation, halomethyl groups are also photoactive.Epoxy groups, allyl ether groups, hydroxyalkyl groups, and unsaturatedammonium, unsaturated phosphonium, and unsaturated ether groups are alsosuitable photoactive groups.

The photopatternable polymers containing these groups can be prepared byany suitable or desired process. For example, the desired functionalgroup or groups can be applied directly to the polymer. Alternatively,one or more intermediate materials can be prepared. For example, thepolymer backbone can be functionalized with a substituent which allowsfor the facile derivatization of the polymer backbone, such as hydroxylgroups, carboxyl groups, haloalkyl groups such as chloromethyl groups,hydroxyalkyl groups such as hydroxymethyl groups, methoxy methyl groups,alkylcarboxymethylene groups, and the like.

Unsaturated ester groups can be placed on the polymer backbone by anysuitable or desired process. For example, substitution of the polymercan be accomplished by reacting the polymer in solution with (a) theappropriate unsaturated acid (such as acrylic acid, methacrylic acid,cinnamic acid, crotonic acid, ethacrylic acid, oleic acid, linoleicacid, maleic acid, fumaric acid, itaconic acid, citraconic acid,phenylmaleic acid, 3-hexene-1,6-dicarboxylic acid, or the like), and (b)a formaldehyde source (i.e., either formaldehyde or a material which,under the conditions of the reaction, generates formaldehyde; examplesof formaldehyde sources in addition to formaldehyde includeparaformaldehyde, trioxane, methylal, dimethoxymethane, and the like).The reaction is direct acid catalyzed; the polymer is dissolved in asuitable solvent and is allowed to react with the formaldehyde source atabout 105° C. in the presence of catalytic amounts ofpara-toluenesulfonic acid. Examples of solvents suitable for thereaction include 1,1,2,2-tetrachloroethane and, if a suitable pressurereactor is used, methylene chloride. Typically, the reactants arepresent in relative amounts with respect to each other (by weight) ofabout 10 parts polymer, about 5 parts formaldehyde source, about 1 partpara-toluenesulfonic acid, about 15.8 parts of the appropriate acid(i.e., acrylic acid, methacrylic acid, or the like), about 0.2 partshydroquinone methyl ether, and about 162 parts1,1,2,2-tetrachloroethane.

The general reaction scheme, illustrated below for the reaction of onespecific group of suitable polymers with acrylic acid, is as follows:

The resulting material is of the general formula

wherein a, b, c, and d are each integers of 0, 1, 2, 3, or 4, providedthat at least one of a, b, c, and d is equal to or greater than 1 in atleast some of the monomer repeat units of the polymer, and n is aninteger representing the number of repeating monomer units. Whenmethacrylic acid is used, the reaction proceeds as shown above exceptthat the

groups shown above are replaced with

groups. When cinnamic acid is used, the reaction proceeds as shown aboveexcept that the

groups shown above are replaced with

groups. Substitution is generally random, although the substituent mayshow a preference for the B group, and any given monomer repeat unit mayhave no substituents, one substituent, or two or more substituents. Themost likely result of the reaction is that a monomer repeat unit willhove 0 or 1 substituents.

Typical reaction temperatures are from about 25 to about 145° C., andpreferably at about 105° C., although the temperature can be outsidethis range. Typical reaction times are from about 1 to about 6 hours,and preferably from about 2 to about 4 hours, although the time can beoutside these ranges. Longer reaction times generally result in higherdegrees of substitution. Higher degrees of substitution generally leadto greater photosensitivity of the polymer, and different degrees ofsubstitution may be desirable for different applications. Too high adegree of substitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation.Too low a degree of substitution may be undesirable because of resultingunnecessarily long exposure times or unnecessarily high exposureenergies. Optimal degrees of substitution generally are from about 0.5to about 1.3 milliequivalents of unsaturated ester groups per gram ofresin. For example, for applications wherein the photopatternablepolymer is to be used as a layer in a thermal ink jet printhead, thedegree of substitution (i.e., the average number of unsaturated estergroups per monomer repeat unit) for polymers of the formula

preferably is from about 0.25 to about 1.2, and more preferably fromabout 0.65 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications.

The polymers can also be substituted with photosensitivity-impartinggroups such as unsaturated ester groups or the like by first preparingthe haloalkylated derivative and then replacing at least some of thehaloalkyl groups with unsaturated ester groups. For example, thehaloalkylated polymer can be substituted with unsaturated ester groupsby reacting the haloalkylated polymer with an unsaturated ester salt insolution. Examples of suitable reactants include selected salts ofGroups IA, IIB, IIIB, IVB, VB, VIB, VIIB, VIIIB, IB, IIB, IIIA, IVA, andthe like, of the periodic table with the appropriate unsaturated ester,such as the ester salts of acrylic acid, methacrylic acid, cinnamicacid, crotonic acid, ethacrylic acid, oleic acid, linoleic acid, maleicacid, fumaric acid, itaconic acid, citraconic acid, phenylmaleic acid,3-hexene-1,6-dicarboxylic acid, and the like, with specific examplesincluding sodium, potassium, quaternary ammonium, phosphonium, and thelike salts of acrylate, methacrylate, cinnamate, and the like. Examplesof solvents suitable for the reaction include polar aprotic solventssuch as N,N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidinone,dimethylformamide, and the like.

The general reaction scheme, illustrated below for the acrylation of aspecific group of chloromethylated polymers, is as follows:

wherein X is any suitable cation, such as sodium, potassium, or thelike, a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0, 1,2, 3, or 4, provided that the sum of i+e is no greater than 4, the sumof j+f is no greater than 4, the sum of k+g is no greater than 4, andthe sum of m+h is no greater than 4, provided that at least one of a, b,c, and d is equal to or greater than 1 in at least some of the monomerrepeat units of the polymer, and provided that at least one of e, f, g,and h is equal to at least 1 in at least some of the monomer repeatunits of the polymer, and n is an integer representing the number ofrepeating monomer units. In the corresponding reaction with themethacrylate salt, the reaction proceeds as shown above except that the

groups shown above are replaced with

groups.

Ether groups and alkylcarboxymethylene groups can also be placed on thechloromethylated polymer by a process analogous to that employed toplace unsaturated ester groups on the chloromethylated polymer, exceptthat the corresponding alkylcarboxylate or alkoxide salt is employed asa reactant. In the corresponding reaction with the alkoxide salt, thereaction proceeds as shown above except that the

groups shown above are replaced with

groups. Suitable ether groups include those wherein R is an alkyl group,preferably with from 1 to about 30 carbon atoms, more preferably withfrom 1 to about 15 carbon atoms, and most preferably with 1 carbon atom.In the corresponding reaction with the alkylcarboxylate salt, thereaction proceeds as shown above except that the

groups shown above are replaced with

groups, wherein R is an alkyl group (including saturated, unsaturated,and cyclic alkyl groups), preferably with from 1 to about 30 carbonatoms, more preferably with from 1 to about 6 carbon atoms, asubstituted alkyl group, an aryl group, preferably with from 6 to about30 carbon atoms, more preferably with from 1 to about 2 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 35 carbon atoms, more preferably with from 7 to about 15 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl, aryl, and arylalkyl groups can be (but are notlimited to) alkoxy groups, preferably with from 1 to about 6 carbonatoms, aryloxy groups, preferably with from 6 to about 24 carbon atoms,arylalkyloxy groups, preferably with from 7 to about 30 carbon atoms,hydroxy groups, amine groups, imine groups, ammonium groups, pyridinegroups, pyridinium groups, ether groups, ester groups, amide groups,carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonate groups,sulfide groups, sulfoxide groups, phosphine groups, phosphonium groups,phosphate groups, mercapto groups, nitroso groups, sulfone groups, acylgroups, acid anhydride groups, azide groups, and the like, wherein twoor more substituents can be joined together to form a ring.

Higher degrees of haloalkylation generally enable higher degrees ofsubstitution with unsaturated ester, ether, and/or alkylcarboxymethylenegroups and thereby enable greater photosensitivity of the polymer.Different degrees of substitution with unsaturated ester, ether, and/oralkylcarboxymethylene groups may be desirable for differentapplications. Too high a degree of substitution may lead to excessivesensitivity, resulting in crosslinking or chain extension of bothexposed and unexposed polymer material when the material is exposedimagewise to activating radiation, whereas too low a degree ofsubstitution may be undesirable because of resulting unnecessarily longexposure times or unnecessarily high exposure energies. Optimum amountsof substitution with unsaturated ester, ether, and/oralkylcarboxymethylene groups are from about 0.8 to about 1.3milliequivalents of unsaturated ester, ether, and/oralkylcarboxymethylene groups per gram of resin. For example, forapplications wherein the photopatternable polymer is to be used as alayer in a thermal ink jet printhead, the degree of substitution (i.e.,the average number of unsaturated ester, ether, and/oralkylcarboxymethylene groups per monomer repeat unit) for polymers ofthe formula

preferably is from about 0.5 to about 1.2, and more preferably fromabout 0.65 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications.

Some or all of the haloalkyl groups can be replaced with unsaturatedester, ether, and/or alkylcarboxymethylene substituents. Longer reactiontimes generally lead to greater degrees of substitution of haloalkylgroups with unsaturated ester, ether, and/or alkylcorboxymethylenesubstituents.

Typical reaction temperatures are from about 20 to about 35° C., andpreferably about 25° C., although the temperature can be outside thisrange. Typical reaction times are from about 30 minutes to about 15days, and preferably from about 2 hours to about 2 days, although thetime can be outside these ranges. The reaction time can be reduced withthe use of a catalyst, such as Adogen 464 (available from AldrichChemical Co., Milwaukee, Wis., or from Ashland Oil Co.), a long chainquaternary ammonium chloride salt, or the like. Adogen 464 is used atapproximately 0.4 weight percent with respect to resin solids, and thiscatalyst results in a doubling of the reaction rate. Adogen 464 issometimes difficult to remove from the product even after several waterand methanol washes. Consequently, this catalyst sometimes results incloudy photoresist solutions. The reaction can be accelerated slightlyby the addition of 0.4 weight percent water, and can be inhibited by theaddition of the same amount of methanol.

The haloalkylated polymer can be allyl ether substituted or epoxidizedby first reacting the haloalkylated polymer with an unsaturated alcoholsalt, such as an allyl alcohol salt, in solution. Examples of suitableunsaturated alcohol salts and allyl alcohol salts include sodium2-allylphenolate, sodium 4-allylphenolate, sodium allyl alcoholate,corresponding salts with lithium, potassium, cesium, rubidium, ammonium,quaternary alkyl ammonium compounds, and the like. An unsaturatedalcohol salt can be generated by the reaction of the alcohol with abase, such as sodium hydride, sodium hydroxide, or the like. The saltdisplaces the halide of the haloalkyl groups at between about 25 andabout 100° C. Examples of solvents suitable for the reaction includepolar aprotic solvents such as N,N-dimethylacetamide, dimethylsulfoxide,N-methylpyrrolidinone, dimethylformamide, tetrahydrofuran, and the like.Typically, the reactants are present in relative amounts with respect toeach other of from about 1 to about 50 molar equivalents of unsaturatedalcohol salt per haloalkyl group to be substituted, although therelative amounts can be outside this range. Typically, the reactants arepresent in solution in amounts of from about 5 to about 50 percent byweight solids, and preferably about 10 percent by weight solids,although the relative amounts can be outside this range.

Typical reaction temperatures are from about 25 to about 100° C., andpreferably from about 25 to about 50° C., although the temperature canbe outside these ranges. Typical reaction times are from about 4 toabout 24 hours, and preferably about 16 hours, although the time can beoutside this range.

The general reaction scheme, illustrated below with a specific class ofchloromethylated polymers and an allyl alcoholate salt, is as follows:

wherein X is any suitable cation, such as sodium, potassium, or thelike, a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0, 1,2, 3, or 4, provided that the sum of i+e is no greater than 4, the sumof j+f is no greater than 4, the sum of k+g is no greater than 4, andthe sum of m+h is no greater than 4, provided that at least one of a, b,c, and d is equal to or greater than 1 in at least some of the monomerrepeat units of the polymer, and provided that at least one of e, f, g,and h is equal to at least 1 in at least some of the monomer repeatunits of the polymer, and n is an integer representing the number ofrepeating monomer units, and n is an integer representing the number ofrepeating monomer units. In the corresponding reaction with the2-allylphenolate salt, the reaction proceeds as shown above except thatthe

groups shown above are replaced with

groups.

The allyl ether substituted polymer is suitable for photoinduced curingreactions. Alternatively, the allyl ether substituted polymer (or theunsaturated ether substituted polymer) can be used as an intermediate inthe synthesis of the epoxidized polymer. This allyl ether or unsaturatedether substituted intermediate product is thereafter reacted with aperoxide, such as hydrogen peroxide, m-chloroperoxybenzoic acid, acetylperoxide, and the like, as well as mixtures thereof, to yield theepoxidized polyarylene ether. Typically, the reactants are present inrelative amounts with respect to each other of from approximatelyequivalent molar amounts of peroxide and the number of unsaturatedgroups desired to be converted to epoxide groups to an excess of between10 and 100 mole percent of peroxide. The reaction preferably takes placein a dilute solution Of about 1 percent by weight solids or less toprevent crosslinking.

The general reaction scheme, illustrated below with the allyl alcoholatesubstituents, is as follows:

wherein a, b, c, d, e, f, g, h, p, q, r, and s are each integers of 0,1, 2, 3, or 4, provided that the sum of a+e+p is no greater than 4, thesum of b+f+q is no greater than 4, the sum of c+g+r is no greater than4, and the sum of d+h+s is no greater than 4, provided that at least oneof p, q, r, and s is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and n is an integer representingthe number of repeating monomer units.

Some or all of the haloalkyl groups can be replaced with allyl ether orepoxy substituents. Longer reaction times generally lead to greaterdegrees of substitution of haloalkyl groups with allyl ether or epoxysubstituents. In one preferred embodiment, some of the haloalkyl groupsremain on the polymer (i.e., at least one of a, b, c, or d is equal toat least 1 in at least some of the monomer repeat units of the polymer).In this embodiment, the polymer can, if desired, be further reacted toconvert the haloalkyl groups to, for example, unsaturated ester groups.

Typical reaction temperatures for the conversion of the unsaturatedether groups to the epoxy groups are from about 0 to about 50° C., andpreferably from about 0 to about 25° C., although the temperature can beoutside these ranges. Typical reaction times are from about 1 to about24 hours, and preferably from about 4 to about 16 hours, although thetime can be outside these ranges. Typical solvents for this reactioninclude methylene chloride, chloroform, carbon tetrachloride, and thelike.

The epoxidized polymer can also be prepared by reaction of thehaloalkylated polymer with an epoxy-group-containing alcohol salt, suchas a glycidolate salt, or an unsaturated alcohol salt, such as those setforth hereinabove, in the presence of a molar excess of base (withrespect to the unsaturated alcohol salt or epoxy-group-containingalcohol salt), such as sodium hydride, sodium hydroxide, potassiumcarbonate, quaternary alkyl ammonium salts, or the like, under phasetransfer conditions. Examples of suitable glycidolate salts includesodium glycidolate and the like. Typically, the reactants are present inrelative amounts with respect to each other of from approximatelyequivalent molar amounts of alcohol and the number of unsaturated groupsdesired to be converted to epoxide groups. Typically, the reactants arepresent in solution in amounts of from about 1 to about 10 percent byweight solids, although other concentrations can be employed. Thereaction with bases such as sodium hydroxide and potassium carbonatetypically takes place at from about 25 to about 100° C. The reactionwith sodium hydride with glycidol or the unsaturated alcohol generallyoccurs at ice bath temperatures. Typical reaction times are about 16hours, although other times may be employed. Examples of suitablesolvents include dimethyl acetamide, tetrahydrofuran, mixtures thereof,and the like.

The general reaction scheme is as follows:

Unsaturated ether or allyl ether groups can also be placed on thehaloalkylated polymer by other methods, such as by a Grignard reaction,a Wittig reaction, or the like.

The haloalkylated polymer can be substituted with aphotosensitivity-imparting, water-solubility-enhancing (orwater-dispersability-enhancing) group by reacting the haloalkylatedpolymer with an unsaturated amine, phosphine, or alcohol, typicallybeing of the general formula

wherein X is

Y is a nitrogen atom or a phosphorus atom, R₁ and R₂ each, independentlyof the other, can be (but are not limited to) hydrogen atoms, alkylgroups, including saturated, unsaturated, and cyclic alkyl groups,preferably with from 1 to about 30 carbon atoms, more preferably withfrom 1 to about 8 carbon atoms, and most preferably with 1 or 2 carbonatoms, substituted alkyl groups, preferably with from 1 to about 30carbon atoms, more preferably with from 1 to about 8 carbon atoms, andmost preferably with 1 or 2 carbon atoms, aryl groups, preferably withfrom 6 to about 30 carbon atoms, more preferably with from 6 to about 18carbon atoms, and most preferably with 6 carbon atoms, substituted arylgroups, preferably with from 6 to about 30 carbon atoms, more preferablywith from 6 to about 18 carbon atoms, and most preferably with 6 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, more preferably with from 7 to about 19 carbon atoms, and mostpreferably with from 7 to about 14 carbon atoms, or substitutedarylalkyl groups, preferably with from 7 to about 30 carbon atoms, morepreferably with from 7 to about 19 carbon atoms, and most preferablywith from 7 to about 14 carbon atoms, wherein R₁ and R₂ can be joined toform a ring, R₃ can be (but is not limited to) an alkyl group, includingsaturated, unsaturated, and cyclic alkyl groups, preferably with from 1to about 30 carbon atoms, more preferably with from 1 to about 8 carbonatoms, and most preferably with 1 or 2 carbon atoms, a substituted alkylgroup, preferably with from 1 to about 30 carbon atoms, more preferablywith from 1 to about 8 carbon atoms, and most preferably with 1 or 2carbon atoms, an aryl group, preferably with from 6 to about 30 carbonatoms, more preferably with from 6 to about 18 carbon atoms, and mostpreferably with 6 carbon atoms, a substituted aryl group, preferablywith from 6 to about 30 carbon atoms, more preferably with from 6 toabout 18 carbon atoms, and most preferably with 6 carbon atoms, anarylalkyl group, preferably with from 7 to about 30 carbon atoms, morepreferably with from 7 to about 19 carbon atoms, and most preferablywith from 7 to about 14 carbon atoms, or a substituted arylalkyl group,preferably with from 7 to about 30 carbon atoms, more preferably withfrom 7 to about 19 carbon atoms, and most preferably with from 7 toabout 14 carbon atoms, R₄, R₅, and R₆ each, independently of the others,are hydrogen atoms, alkyl groups, including saturated, unsaturated, andcyclic alkyl groups, preferably with from 1 to about 30 carbon atoms,more preferably with from 1 to about 8 carbon atoms, and most preferablywith 1 or 2 carbon atoms, substituted alkyl groups, preferably with from1 to about 30 carbon atoms, more preferably with from 1 to about 8carbon atoms, and most preferably with 1 or 2 carbon atoms, aryl groups,preferably with from 6 to about 30 carbon atoms, more preferably withfrom 6 to about 18 carbon atoms, and most preferably with 6 carbonatoms, substituted aryl groups, preferably with from 6 to about 30carbon atoms, more preferably with from 6 to about 18 carbon atoms, andmost preferably with 6 carbon atoms, arylalkyl groups, preferably withfrom 7 to about 30 carbon atoms, more preferably with from 7 to about 19carbon atoms, and most preferably with from 7 to about 14 carbon atoms,or substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, more preferably with from 7 to about 19 carbon atoms, andmost preferably with from 7 to about 14 carbon atoms, and mostpreferably are hydrogen atoms, wherein two or more of R₄, R₅, and R₆ canbe joined together to form a ring, and R₇ and R₈ each, independently ofthe other, can be (but are not limited to) hydrogen atoms, alkyl groups,including saturated, unsaturated, and cyclic alkyl groups, preferablywith from 1 to about 30 carbon atoms, more preferably with from 1 toabout 8 carbon atoms, and most preferably with 1 or 2 carbon atoms,substituted alkyl groups, preferably with from 1 to about 30 carbonatoms, more preferably with from 1 to about 8 carbon atoms, and mostpreferably with 1 or 2 carbon atoms, aryl groups, preferably with from 6to about 30 carbon atoms, more preferably with from 6 to about 18 carbonatoms, and most preferably with 6 carbon atoms, substituted aryl groups,preferably with from 6 to about 30 carbon atoms, more preferably withfrom 6 to about 18 carbon atoms, and most preferably with 6 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, more preferably with from 7 to about 19 carbon atoms, and mostpreferably with from 7 to about 14 carbon atoms, or substitutedarylalkyl groups, preferably with from 7 to about 30 carbon atoms, morepreferably with from 7 to about 19 carbon atoms, and most preferablywith from 7 to about 14 carbon atoms. Examples of suitable substituentson substituted alkyl groups, substituted aryl groups, and substitutedarylalkyl groups can be (but are not limited to) hydroxy groups, aminegroups, imine groups, ammonium groups, pyridine groups, pyridiniumgroups, ether groups, aldehyde groups, ketone groups, ester groups,amide groups, carboxylic acid groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, cyanogroups, nitrile groups, mercapto groups, nitroso groups, halogen atoms,nitro groups, sulfone groups, acyl groups, acid anhydride groups, azidegroups, mixtures thereof, and the like, wherein two or more substituentscan be joined together to form a ring. Alternatively, the combination ofR₃ and X can be a group of the formula

—[(CRR′)_(x)O]_(y)

 wherein x is an integer of from 1 to about 6, and preferably from 1 toabout 3, y is an integer of from 1 to about 50, and preferably from 1 toabout 20, and R and R′ each, independently of the other, can be (but arenot limited to) hydrogen atoms, alkyl groups, preferably with from 1 to2 carbon atoms, and the like. Examples of suitable reactants of theseformulae include N,N-dimethyl ethyl methacrylate, N,N-dimethyl ethylacrylate,

wherein R is H or CH₃ and n is an integer of from 1 to about 50, and thelike. Examples of solvents suitable for the reaction include polaraprotic solvents such as N,N-dimethylacetamide, dimethylsulfoxide,N-methylpyrrolidinone, dimethylformamide, and the like. Typically, thereactants are present in relative amounts with respect to each other ofabout 10 parts by weight haloalkylated polymer, about 23 parts by weightsolvent, and about 0.1 to about 5.5 parts by weight unsaturated amine,phosphine, or alcohol.

The general reaction scheme to place unsaturated ammonium or phosphoniumgroups on the polymer, illustrated below for the reaction of a specificclass of chloromethylated polymers with N,N-dimethylethyl methacrylate,is as follows:

Or, more generally,

wherein a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units.

Some or all of the haloalkyl groups can be replaced withphotosensitivity-imparting, water-solubility-enhancing (orwater-dispersability-enhancing) substituents. Longer reaction timesgenerally lead to greater degrees of substitution of haloalkyl groupswith photosensitivity-imparting, water-solubility-enhancing (orwater-dispersability-enhancing) substituents.

Typical reaction temperatures are from about 0 to about 40° C., andpreferably from about 10 to about 25° C., although the temperature canbe outside these ranges. Typical reaction times are from about 1 toabout 16 hours, and preferably from about 1 to about 4 hours, althoughthe time can be outside these ranges.

In another embodiment, the polymer is substituted with two differentfunctional groups, one of which imparts photosensitivity to the polymerand one of which imparts water solubility or water dispersability to thepolymer. Either substituent may be placed on the polymer first, followedby the reaction to place the other substituent. In some instances,placement of the photosensitivity-imparting group, such as anunsaturated ester group, first, may be preferred because subsequentmeasurement of the degree of substitution by thephotosensitivity-imparting group may be easier without othersubstituents, such as water-solubility-imparting groups orwater-dispersability-imparting groups, being present. Examples ofreactants which can be reacted with the polymer to substitute thepolymer with suitable water solubility enhancing groups or waterdispersability enhancing groups include tertiary amines of the generalformula

which add to the polymer quaternary ammonium groups of the generalformula

wherein R₁, R₂, and R₃ each, independently of the others, can be) butare not limited to) alkyl groups, typically with from 1 to about 30carbon atoms, substituted alkyl groups, aryl groups, typically with from6 to about 18 carbon atoms, substituted aryl groups, arylalkyl groups,typically with from 7 to about 19 carbon atoms, and substitutedarylalkyl groups, and X represents a halogen atom, such as fluorine,chlorine, bromine, or iodine; tertiary phosphines of the general formula

which add to the polymer quaternary phosphonium groups of the generalformula

wherein R₁, R₂, and R₃ each, independently of the others, can be (butare not limited to) alkyl groups, typically with from 1 to about 30carbon atoms, substituted alkyl groups, aryl groups, typically with from6 to about 18 carbon atoms, substituted aryl groups, arylalkyl groups,typically with from 7 to about 19 carbon atoms, and substitutedarylalkyl groups, and X represents a halogen atom, such as fluorine,chlorine, bromine, or iodine; alkyl thio ethers of the general formula

R₁—S—R₂

which add to the polymer sulfonium groups of the general formula

wherein R₁ and R₂ each, independently of the other, can be (but are notlimited to) alkyl groups, typically with from 1 to about 6 carbon atomsand preferably with 1 carbon atom, and substituted alkyl groups, and Xrepresents a halogen atom, such as fluorine, chlorine, bromine, oriodine; wherein the substituents on the substituted alkyl, aryl, andarylalkyl groups can be (but are not limited to) hydroxy groups, aminegroups, imine groups, ammonium groups, pyridine groups, pyridiniumgroups, ether groups, aldehyde groups, ketone groups, ester groups,amide groups, carboxylic acid groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, cyanogroups, nitrile groups, mercapto groups, nitroso groups, halogen atoms,nitro groups, sulfone groups, acyl groups, acid anhydride groups, azidegroups, mixtures thereof, and the like, wherein two or more substituentscan be joined together to form a ring.

These water solubility imparting substituents or water dispersabilityimparting substituents can be placed on the polymer by any suitable ordesired process. For example, two equivalents of the nucleophilicreagent (amine, phosphine, or thio ether) can be allowed to react withone equivalent of the haloalkylated polymer at 25° C. in a polar aproticsolvent such as dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidinone, dimethyl formamide, or the like, with the reactantspresent in the solvent in a concentration of about 30 percent by weightsolids. Reaction times typically are from about 1 to about 24 hours,with 2 hours being typical.

Alternatively, the water solubility imparting group or waterdispersability imparting group can be nonionic, such as a group of theformula

—[(CRR′)_(x)O]_(y)R″

wherein x is an integer of from 1 to about 6, and preferably from 1 toabout 3, y is an integer of from 1 to about 50, and preferably from 1 toabout 20, and R, R′, and R″ each, independently of the others, can be(but are not limited to) hydrogen atoms, alkyl groups, preferably withfrom 1 to 2 carbon atoms, substituted alkyl groups, aryl groups,preferably with from 6 to about 12 carbon atoms, substituted arylgroups, arylalkyl groups, preferably with from 7 to about 13 carbonatoms, substituted arylalkyl groups, and the like, wherein thesubstituents on the substituted alkyl, aryl, and arylalkyl groups can be(but are not limited to) hydroxy groups, amine groups, imine groups,ammonium groups, pyridine groups, pyridinium groups, ether groups,aldehyde groups, ketone groups, ester groups, amide groups, carboxylicacid groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, cyano groups, nitrile groups,mercapto groups, nitroso groups, halogen atoms, nitro groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, mixturesthereof, and the like, wherein two or more substituents can be joinedtogether to form a ring. Substituents of this formula can be placed onthe polymer by, for example, reacting from about 2 to about 10milliequivalents of a salt of the —[(CRR′)_(x)O]_(y)R″ group (such as analkali metal salt or the like) with 1 equivalent of the haloalkylatedpolymer in a polar aprotic solvent such as tetrahydrofuran,dimethylacetamide, dimethyl sulfoxide, N-methyl pyrrolidinone, dimethylformamide, or the like, in the presence of a base, such as at leastabout 2 equivalents of sodium hydroxide, at least about 1 equivalent ofsodium hydride, or the like, at about 80° C. for about 16 hours. Longerpolyether chains tend to impart more hydrophilic character to thepolymer. The substitution of poly (vinyl benzyl chloride) polymers withpolyether chains is disclosed in further detail in, for example,Japanese Patent Kokai 78-79,833 (1978) and in Chem. Abstr., 89, 180603(1978), the disclosures of each of which are totally incorporated hereinby reference.

Higher degrees of haloalkylation generally enable higher degrees ofsubstitution with water solubility imparting groups or waterdispersability imparting groups. Different degrees of substitution maybe desirable for different applications. The degree of substitution(i.e., the average number of water solubility imparting groups or waterdispersability imparting groups per monomer repeat unit) typically isfrom about 0.25 to about 4.0, and preferably from about 0.5 to about 2,although the degree of substitution can be outside these ranges. Optimumamounts of substitution are from about 0.8 to about 2 milliequivalentsof water solubility imparting group or water dispersability impartinggroup per gram of resin, and preferably from about 1 to about 1.5milliequivalents of water solubility imparting group or waterdispersability imparting group per gram of resin.

The hydroxymethylation of a polymer can be accomplished by reacting thepolymer in solution with formaldehyde or paraformaldehyde and a base,such as sodium hydroxide, potassium hydroxide, calcium hydroxide,ammonium hydroxide, tetramethylammonium hydroxide, or the like. Thepolymer is dissolved in a suitable solvent, such as1,1,2,2-tetrachloroethane or the like, and is allowed to react with theformaldehyde or paraformaldehyde. Examples of solvents suitable for thereaction include 1,1,2,2-tetrachloroethane, as well as methylenechloride, provided a suitable pressure reactor is used. Typically, thereactants are present in relative amounts by weight of about 44.5 partsparaformaldehyde or 37 parts formaldehyde, about 1 part base, about 200parts 1,1,2,2-tetrachloroethane, and about 100 parts polymer.

The general reaction scheme is as follows:

wherein a, b, c, and d are each integers of 0, 1, 2, 3, or 4, providedthat at least one of a, b, c, and d is equal to or greater than 1 in atleast some of the monomer repeat units of the polymer, and n is aninteger representing the number of repeating monomer units. Substitutionis generally random, although the substituent often indicates apreference for the B group, and a particular preference for the sitesortho to oxygen on the B group, and any given monomer repeat unit mayhave no hydroxymethyl substituents, one hydroxymethyl substituent, ortwo or more hydroxymethyl substituents. Most commonly, each aromaticring will have either no hydroxymethyl groups or one hydroxymethylgroup.

Typical reaction temperatures are from about 50 to about 125° C., andpreferably from about 85 to about 110° C., although the temperature canbe outside these ranges. Typical reaction times are from about 4 toabout 24 hours, and preferably from about 4 to about 6 hours, althoughthe time can be outside these ranges. Longer reaction times generallyresult in higher degrees of hydroxymethylation. Different degrees ofhydroxymethylation may be desirable for different applications. Too higha degree of substitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. Optimal degrees of substitution generally are fromabout 0.8 to about 1.3 milliequivalents of hydroxymethyl per gram ofresin. For example, for applications wherein the photopatternablepolymer is to be used as a layer in a thermal ink jet printhead, thedegree of substitution (i.e., the average number of hydroxymethyl groupsper monomer repeat unit) for polymers of the formula

preferably is from about 0.25 to about 2.0, and more preferably fromabout 0.5 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications.

Polymers can also be hydroxyalkylated by first preparing thehaloalkylated derivative and then replacing at least some of thehaloalkyl groups with hydroxyalkyl groups. For example, thehaloalkylated polymer can be hydroxyalkylated by alkaline hydrolysis ofthe haloalkylated polymer. The hydroxy groups replace the halide atomsin the haloalkyl groups on the polymer; accordingly, the number ofcarbon atoms in the haloalkyl group generally corresponds to the numberof carbon atoms in the hydroxyalkyl group. Examples of suitablereactants include sodium hydroxide, potassium hydroxide, calciumhydroxide, ammonium hydroxide, tetraalkyl ammonium hydroxides, such astetrabutyl ammonium hydroxide, and the like. Examples of solventssuitable for the reaction include 1,1,2,2-tetrachloroethane, methylenechloride, and water. Typically, the reactants are present in relativeamounts with respect to each other by weight of about 13.8 partshaloalkylated polymer, about 50 parts solvent, and about 30.6 parts base(containing 23 parts tetrabutylommonium hydroxide in water). After aclear solution is obtained, 30 milliliters of sodium hydroxide (50percent aqueous solution) is added. After 16 hours at about 25° C., theorganic layer is washed with water, dried over magnesium sulfate, andpoured into methanol (1 gallon) to precipitate the polymer.

The general reaction scheme, illustrated below for a specific class ofchloromethylated polymers, is as follows:

wherein a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units.

Higher degrees of haloalkylation generally enable higher degrees ofsubstitution with hydroxyalkyl groups, and thereby enable greaterphotosensitivity of the polymer. Different degrees of substitution maybe desirable for different applications. Too high a degree ofsubstitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. Optimum amounts of substitution are from about 0.8 toabout 1.3 milliequivalents of hydroxyalkyl group per gram of resin. Forexample, for applications wherein the photopatternable polymer is to beused as a layer in a thermal ink jet printhead, the degree ofsubstitution (i.e., the average number of hydroxyalkyl groups permonomer repeat unit) for polymers of the formula

preferably is from about 0.25 to about 2.0, and more preferably fromabout 0.5 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications.

Some or all of the haloalkyl groups can be replaced with hydroxyalkylsubstituents. Longer reaction times generally lead to greater degrees ofsubstitution of haloalkyl groups with hydroxyalkyl substituents.

Typical reaction temperatures are from about 25 to about 120° C., andpreferably from about 25 to about 50° C., although the temperature canbe outside this range. Typical reaction times are from about 1 to about24 hours, and preferably from about 10 to about 16 hours, although thetime can be outside these ranges.

Intermediate derivatives can also be prepared by any suitable or desiredprocess. For example, suitable processes for haloalkylating polymersinclude reaction of the polymers with formaldehyde and hydrochloricacid, bischloromethyl ether, chloromethyl methyl ether,octylchloromethyl ether, or the like, generally in the presence of aLewis acid catalyst. Bromination of a methyl group on the polymer canalso be accomplished with elemental bromine via a free radical processinitiated by, for example, a peroxide initiator or light. Halogen atomscan be substituted for other halogens already on a halomethyl group by,for example, reaction with the appropriate hydrohalic acid or halidesalt. Methods for the haloalkylation of polymers are also disclosed in,for example, “Chloromethylation of Condensation Polymers Containing anOxy-1,4-Phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference.

One specific process suitable for haloalkylating the polymer entailsreacting the polymer with an acetyl halide, such as acetyl chloride, anddimethoxymethane in the presence of a halogen-containing Lewis acidcatalyst, such as those of the general formula

M^(n⊕)X_(n)

wherein n is an integer of 1, 2, 3, 4, or 5, M represents a boron atomor a metal atom, such as tin, aluminum, zinc, antimony, iron (III),gallium, indium, arsenic, mercury, copper, platinum, palladium, or thelike, and X represents a halogen atom, such as fluorine, chlorine,bromine, or iodine, with specific examples including SnCl₄, AlCl₃,ZnCl₂, AlBr₃, BF₃, SbF₅, Fel₃, GaBr₃, InCl₃, Asl₅, HgBr₂, CuCl, PdCl₂,PtBr₂, or the like. Care must be taken to avoid cross-linking of thehaloalkylated polymer. Typically, the reactants are present in relativeamounts by weight of about 35.3 parts acetyl halide, about 37 partsdimethoxymethane, about 1.2 parts methanol, about 0.3 parts Lewis acidcatalyst, about 446 parts 1,1,2,2-tetrachlorethane, and about 10 to 20parts polymer. 1,1,2,2-Tetrachlorethane is a suitable reaction solvent.Dichloromethane is low boiling, and consequently the reaction is slow inthis solvent unless suitable pressure equipment is used.

The general reaction scheme is as follows:

wherein R′ and R″ each, independently of the other, can be (but are notlimited to) hydrogen atoms, alkyl groups, including saturated,unsaturated, and cyclic alkyl groups, preferably with from 1 to about 11carbon atoms, substituted alkyl groups, preferably with from 1 to about11 carbon atoms, aryl groups, preferably with from 6 to about 11 carbonatoms, substituted aryl groups, preferably with from 6 to about 11carbon atoms, arylalkyl groups, preferably with from 7 to about 11carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 11 carbon atoms, and the like. The resulting material is of thegeneral formula

wherein n is an integer of 1, 2, 3, 4, or 5, R is an alkyl group,including both saturated, unsaturated, linear, branched, and cyclicalkyl groups, preferably with from 1 to about 11 carbon atoms, morepreferably with from 1 to about 5 carbon atoms, even more preferablywith from 1 to about 3 carbon atoms, and most preferably with 1 carbonatom, or a substituted alkyl group, an arylalkyl group, preferably withfrom 7 to about 29 carbon atoms, more preferably with from 7 to about 17carbon atoms, even more preferably with from 7 to about 13 carbon atoms,and most preferably with from 7 to about 9 carbon atoms, or asubstituted arylalkyl group, and X is a halogen atom, such as fluorine,chlorine, bromine, or iodine, or a, b, c, and d are each integers of 0,1, 2, 3, or 4, provided that at least one of a, b, c, and d is equal toor greater than 1 in at least some of the monomer repeat units of thepolymer, and n is an integer representing the number of repeatingmonomer units. Examples of suitable substituents on the substitutedalkyl, aryl, and arylalkyl groups include (but are not limited to) alkylgroups, including saturated, unsaturated, linear, branched, and cyclicalkyl groups, preferably with from 1 to about 6 carbon atoms,substituted alkyl groups, preferably with from 1 to about 6 carbonatoms, aryl groups, preferably with from 6 to about 24 carbon atoms,substituted aryl groups, preferably with from 6 to about 24 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, alkoxy groups, preferably with from 1 to about 6 carbonatoms, substituted alkoxy groups, preferably with from 1 to about 6carbon atoms, aryloxy groups, preferably with from 6 to about 24 carbonatoms, substituted aryloxy groups, preferably with from 6 to about 24carbon atoms, arylalkyloxy groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, amine groups, imine groups, ammonium groups,pyridine groups, pyridinium groups, ether groups, ester groups, amidegroups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonategroups, sulfide groups, sulfoxide groups, phosphine groups, phosphoniumgroups, phosphate groups, mercapto groups, nitroso groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, and the like,wherein the substituents on the substituted alkyl groups, substitutedaryl groups, substituted arylalkyl groups, substituted alkoxy groups,substituted aryloxy groups, and substituted arylalkyloxy groups can be(but are not limited to) hydroxy groups, amine groups, imine groups,ammonium groups, pyridine groups, pyridinium groups, ether groups,aldehyde groups, ketone groups, ester groups, amide groups, carboxylicacid groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, cyano groups, nitrile groups,mercapto groups, nitroso groups, halogen atoms, nitro groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, mixturesthereof, and the like, wherein any two or more substituents can bejoined together to form a ring. Substitution is generally random,although the substituent often indicates a preference for the B group,and any given monomer repeat unit may have no haloalkyl substituents,one haloalkyl substituent, or two or more haloalkyl substituents,wherein a, b, c, and d are each integers of 0, 1, 2, 3, or 4, providedthat at least one of a, b, c, and d is equal to or greater than 1 in atleast some of the monomer repeat units of the polymer, and n is aninteger representing the number of repeating monomer units. Substitutionis generally random, although the substituent often indicates apreference for the B group, and any given monomer repeat unit may haveno haloalkyl substituents, one haloalkyl substituent, or two or morehaloalkyl substituents.

Typical reaction temperatures are from about 60 to about 120° C., andpreferably from about 80 to about 110° C., although the temperature canbe outside these ranges. Typical reaction times are from about 1 toabout 10 hours, and preferably from about 2 to about 4 hours, althoughthe time can be outside these ranges. Longer reaction times generallyresult in higher degrees of haloalkylation. When the haloalkylatedpolymer is used as an intermediate material in the synthesis of polymerssubstituted with photoactive groups such as unsaturated ester groups,higher degrees of haloalkylation generally enable higher degrees ofsubstitution with photoactive groups and thereby enable greaterphotosensitivity of the polymer. Different degrees of haloalkylation maybe desirable for different applications. When the material is used as anintermediate in the synthesis of the polymer substituted withunsaturated ester groups, too high a degree of substitution may lead toexcessive sensitivity, resulting in crosslinking or chain extension ofboth exposed and unexposed polymer material when the material is exposedimagewise to activating radiation, whereas too low a degree ofsubstitution may be undesirable because of resulting unnecessarily longexposure times or unnecessarily high exposure energies. For example, forapplications wherein the photopatternable polymer is to be used as alayer in a thermal ink jet printhead, the degree of substitution (i.e.,the average number of unsaturated ester groups per monomer repeat unit)for polymers of the formula

preferably is from about 0.5 to about 1.2, and more preferably fromabout 0.7 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications. Thehalomethylated polymer can also be used as a photoresist in its ownright when energy sources such as electron beams, deep ultravioletlight, or the like are used.

Other procedures for placing functional groups on aromatic polymers aredisclosed in, for example, W. H. Daly, S. Chotiwana, and R. Nielsen,Polymer Preprints, 20(1), 835 (1979); “Functional Polymers andSequential Copolymers by Phase Transfer Catalysis, 3. Synthesis AndCharacterization of Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol. Chem., 185, 2319 (1984); F. Wangand J. Roovers, Journal of Polymer Science: Part A: Polymer Chemistry,32, 2413 (1994); “Details Concerning the Chloromethylation of SolubleHigh Molecular Weight Polystyrene Using Dimethoxymethane, ThionylChloride, And a Lewis Acid: A Full Analysis,” M. E. Wright, E. G.Toplikar, and S. A. Svejda, Macromolecules, 24, 5879 (1991); “FunctionalPolymers and Sequential Copolymers by Phase Transfer Catalysts,” V.Percec and P. L. Rinaldi, Polymer Bulletin, 10, 223 (1983); “Preparationof Polymer Resin and Inorganic Oxide Supported Peroxy-Acids and TheirUse in the Oxidation of Tetrahydrothiophene,” J. A. Greig, R. D.Hancock, and D. C. Sherrington, Euopean Polymer J., 16, 293 (1980);“Preparation of Poly(vinylbenzyltriphenylphosphonium Perbromide) and ItsApplication in the Bromination of Organic Compounds,” A. Akelah, M.Hassanein, and F. Abdel-Galil, European Polymer J., 20 (3) 221 (1984);J. M. J. Frechet and K. K. Haque, Macromelcules, 8, 130 (1975); U.S.Pat. No. 3,914,194; U.S. Pat. No. 4,110,279; U.S. Pat. No. 3,367,914;“Synthesis of Intermediates for Production of Heat Resistant Polymers(Chloromethylation of Diphenyl oxide),” E. P. Tepenitsyna, M. I.Farberov, and A. P. Ivanovski, Zhurnal Prikladnoi Khimii, Vol. 40, No.11, 2540 (1967); U.S. Pat. No. 3,000,839; Chem Abst. 56, 590f (1962);U.S. Pat. No. 3,128,258; Chem Abstr. 61, 4560a (1964); J. D. Doedens andH. P. Cordts, Ind. Eng. Ch., 83, 59 (1961); British Patent 863,702; andChem Abstr 55, 18667b (1961); the disclosures of each of which aretotally incorporated herein by reference.

The polymers of the present invention also contain at least one thermalsensitivity-imparting substituent which enables further crosslinking orchain extension of the polymer upon exposure to temperatures of about140° C. and higher. Examples of suitable thermal sensitivity impartinggroups include ethynyl groups, such as those of the formula

—(R)_(a)—C≡C—R′

wherein R is

a is an integer of 0 or 1, and R′ is a hydrogen atom or a phenyl group,ethylenic linkage-containing groups, such as allyl groups, includingthose of the formula

 wherein X and Y each, independently of the other, are hydrogen atoms orhalogen atoms, such as fluorine, chlorine, bromine, or iodine, vinylgroups, including those of the formula

 wherein R is an alkyl group, including both saturated, unsaturated,linear, branched, and cyclic alkyl groups, preferably with from 1 toabout 30 carbon atoms, more preferably with from 1 to about 11 carbonatoms, even more preferably with from 1 to about 5 carbon atoms, asubstituted alkyl group, an aryl group, preferably with from is to about24 carbon atoms, more preferably with from 6 to about 18 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 30 carbon atoms, more preferably with from 7 to about 19 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein any two ormore substituents can be joined together to form a ring, vinyl ethergroups, such as those of the formula

 epoxy groups, including those of the formula

R is an alkyl group, including both saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 30carbon atoms, more preferably with from 1 to about 11 carbon atoms, evenmore preferably with from 1 to about 5 carbon atoms;, a substitutedalkyl group, an aryl group, preferably with from 6 to about 24 carbonatoms, more preferably with from 6 to about 18 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 30 carbon atoms, more preferably with from 7 to about 19 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein any two ormore substituents can be joined together to form a ring, halomethylgroups, such as fluoromethyl groups, chloromethyl groups, bromomethylgroups, and iodomethyl groups, hydroxymethyl groups, benzocyclobutenegroups, including those of the formula

 phenolic groups (-φ-OH), provided that the phenolic groups are presentin combination with either halomethyl groups or hydroxymethyl groups;the halomethyl groups or hydroxymethyl groups can be present on the samepolymer bearing the phenolic groups or on a different polymer, or on amonomeric species present with the phenolic group substituted polymer;maleimide groups, such as those of the formula

 biphenylene groups, such as those of the formula

 5-norbornene-2,3-dicarboximido (nadimido) groups, such as those of theformula

 alkylcarboxylate groups, such as those of the formula

 wherein R is an alkyl group (including saturated, unsaturated, andcyclic alkyl groups), preferably with from 1 to about 30 carbon atoms,more preferably with from 1 to about 6 carbon atoms, a substituted alkylgroup, an aryl group, preferably with from 6 to about 30 carbon atoms,more preferably with from 1 to about 2 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 35 carbonatoms, more preferably with from 7 to about 15 carbon atoms, or asubstituted arylalkyl group, wherein the substituents on the substitutedalkyl, aryl, and arylalkyl groups can be (but are not limited to) alkoxygroups, preferably with from 1 to about 6 carbon atoms, aryloxy groups,preferably with from 6 to about 24 carbon atoms, arylalkyloxy groups,preferably with from 7 to about 30 carbon atoms, hydroxy groups, aminegroups, imine groups, ammonium groups, pyridine groups, pyridiniumgroups, ether groups, ester groups, amide groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, mercapto groups, nitroso groups, sulfone groups, acyl groups,acid anhydride groups, azide groups, and the like, wherein two or moresubstituents can be joined together to form a ring, and the like.

The thermal sensitivity imparting groups can be present either asterminal end groups on the polymer or as groups which are pendant fromone or more monomer repeat units within the polymer chain. When thethermal sensitivity imparting groups are present as terminal end groups,one or both polymer ends can be terminated with the thermal sensitivityimparting group (or more, if the polymer is crosslinked and has morethan two termini). When the thermal sensitivity imparting groups aresubstituents on one or more monomer repeat units of the polymer, anydesired or suitable degree of substitution can be employed. Preferably,the degree of substitution is from about 1 to about 4 thermalsensitivity imparting groups per repeat monomer unit, although thedegree of substitution can be outside this range. Preferably, the degreeof substitution is from about 0.5 to about 5 milliequivalents of thermalsensitivity imparting group per gram of polymer, and more preferablyfrom about 0.75 to about 1.5 milliequivalents per gram, although thedegree of substitution can be outside this range.

The thermal sensitivity imparting groups can be placed on the polymer byany suitable or desired synthetic method. Processes for putting theabove mentioned thermal sensitivity imparting groups on polymers aredisclosed in, for example, “Polyimides,” C. E. Sroog, Prog. Polym. Sci.,Vol. 16, 561-694 (1991); F. E. Arnold and L. S. Tan, Symposium on RecentAdvances in Polyimides and Other High Performance Polymers, Reno, Nev.(July 1987); L. S. Tan and F. E. Arnold, J. Polym. Sci. Part A, 26, 1819(1988); U.S. Pat. No. 4,973,636; and U.S. Pat. No. 4,927,907; thedisclosures of each of which are totally incorporated herein byreference.

Other procedures for placing thermally curable end groups on aromaticpolymers are disclosed in, for example, P. M. Hergenrother, J. Macromol.Sci. Rev. Macromol. Chem., C19 (1), 1-34 (1980); V. Percec and B. C.Auman, Makromol. Chem., 185, 2319 (1984); S. J. Havens, and P. M.Hergenrother, J. of Polymer Science: Polymer Chemistry Edition, 22, 3011(1984); P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 20, 3131 (1982); V. Percec, P. L. Rinaldi, and B. C. Auman,Polymer Bulletin, 10, 215 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 2. Synthesis andCharacterization of Aromatic Poly(ether sulfones Containing Vinylbenzyland Ethynylbenzyl Chain Ends,” V. Percec and B. C. Auman, Makromol.Chem. 185, 1867 (1984); “Functional Polymers and Sequential Copolymersby Phase Transfer Catalysis, 6. On the Phase Transfer CatalyzedWilliamson Polyetherification as a New Method for the Preparation ofAlternating Block copolymers,” V. Percec, B. Auman, and P. L. Rinaldi,Polymer Bulletin, 10, 391 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 3 Synthesis and Characterizationof Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol. Chem., 185, 2319 (1984); and “PhaseTransfer Catalysis, Functional Polymers and Sequential Copolymers byPTC,5. Synthesis and Characterization of Polyformals of PolyetherSulfones,” Polymer Bulletin, 10, 385 (1983); the disclosures of each ofwhich are totally incorporated herein by reference.

In some instances a functional group can behave as either aphotosensitivity-imparting group or a thermal sensitivity impartinggroup. For the polymers of the present invention, at least two differentgroups are present on the polymer, one of which functions primarily as aphotosensitivity-imparting group and one of which functions primarily asa thermal sensitivity imparting group. Either the two groups areselected so that the thermal sensitivity imparting group does not reactor crosslink when exposed to actinic radiation at a level to which thephotosensitivity-imparting group is sensitive, or photocuring is haltedwhile at least some thermal sensitivity imparting groups remain intactand unreacted or uncrosslinked on the polymer. Typically (although notnecessarily) the thermal sensitivity imparting group is one which reactsat a temperature in excess of the glass transition temperature of thepolymer subsequent to crosslinking or chain extension via photoexposure.

The polymers of the present invention are cured in a two-stage processwhich entails (a) exposing the polymer to actinic radiation, therebycausing the polymer to become crosslinked or chain extended through thephotosensitivity-imparting groups; and (b) subsequent to step (a),heating the polymer to a temperature of at least 140° C., therebycausing further crosslinking or chain extension of the polymer throughthe thermal sensitivity imparting groups.

The temperature selected for the second, thermal cure step generallydepends on the thermal sensitivity imparting group which is present onthe polymer. For example, ethynyl groups preferably are cured attemperatures of from about 150 to about 300° C. Halomethyl groupspreferably are cured at temperatures of from about 150 to about 260° C.Hydroxymethyl groups preferably are cured at temperatures of from about150 to about 250° C. Phenylethynyl phenyl groups preferably are cured attemperatures of greater than about 250° C. Vinyl groups preferably arecured at temperatures of from about 80 to about 250° C. Allyl groupspreferably are cured at temperatures of over about 200° C. Epoxy groupspreferably are cured at temperatures of about 150° C. Maleimide groupspreferably are cured at temperatures of from about 200 to about 300° C.Benzocyclobutene groups preferably are cured at temperatures of overabout 200° C. 5-Norbornene-2,3-dicarboximidogroups preferably are curedat temperatures of from about 200 to about 300° C. Vinyl ether groupspreferably are cured at temperatures of about 150° C. Phenolic groups inthe presence of hydroxymethyl or halomethyl groups preferably are curedat temperatures of from about 150 to about 210° C. Alkylcarboxylategroups preferably are cured at temperatures of from about 150 to about250° C. Curing temperatures usually do not exceed about 400° C.,although higher temperatures can be employed provided that decompositionof the polymer does not occur. Higher temperature cures preferably takeplace in an oxygen-excluded environment.

Reaction of the phenylethynyl end groups serves to chain-extend thenetwork. Hydroxymethyl and halo groups are also preferred when thephotopatternable polymer has a glass transition temperature of less thanabout 150° C. Hydroxymethyl and halomethyl groups on phenolic ends areparticularly reactive and serve to chain-extend the network. The factthat this chain extension occurs at temperatures significantly in excessof the glass transition temperature of the polymer facilitates the chainextension reaction, relaxes stresses in the crosslinked film, and allowsfor the extrusion of thermally labile alkyl fragments introduced in thephotoactivation of the backbone. Phenolic end groups can be obtained byadjusting the stoichiometry of the coupling reaction in the formation ofpolyarylene ether ketones; for example, excess bisphenol A is used whenbisphenol A is the B group. Halomethyl groups are particularlypreferred. Halomethyl groups react at a temperature in excess of 150° C.and extensively crosslink the polymer by the elimination of hydrochloricacid and the formation of methylene bridges. When the photoexposedcrosslinked polymer has a glass transition temperature of less thanabout 150° C., halomethyl groups are particularly preferred. The factthat this chain extension and crosslinking occurs at temperaturessignificantly in excess of the glass transition temperature of thepolymer facilitates the chain extension reaction, relaxes stresses inthe cross-linked film, and allows for the extrusion of thermally labilealkyl fragments introduced in the photoactivation of the backbone. Thethermal reaction is believed to eliminate hydrohalic acid and to linkpolymer chains with methylene bridges. Crosslinking of the halomethylgroups begins near 150° C. and proceeds rapidly in the temperature rangeof from about 180 to about 210° C.

Further information regarding photoresist compositions is disclosed in,for example, J. J. Zupancic, D. C. Blazej, T. C. Baker, and E. A.Dinkel, Polymer Preprints, 32, (2), 178 (1991); “High PerformanceElectron Negative Resist, Chloromethylated Polystyrene. A Study onMolecular Parameters,” S. Imamura, T. Tamamura, and K. Harada, J. ofApplied Polymer Science, 27, 937 (1982); “Chloromethylated Polystyreneas a Dry Etching-Resistant Negative Resist for Submicron Technology”, S.Imamura, J. Electrochem. Soc.: Solid-state Science and Technology,126(9), 1628 (1979); “UV curing of composites based on modifiedunsaturated polyesters,” W. Shi and B. Ranby, J. of Applied PolymerScience, Vol. 51, 1129 (1994); “Cinnamates VI. Light-Sensitive Polymerswith Pendant o-, m- and p-hydroxycinnamate Moieties,” F. Scigalski, M.Toczek, and J. Paczkowski, Polymer, 35, 692 (1994); and “Radiation-curedPolyurethane Methacrylate Pressure-sensitive Adhesives,” G. Ansell andC. Butler, Polymer, 35 (9), 2001 (1994), the disclosures of each ofwhich are totally incorporated herein by reference.

In some instances, the terminal groups on the polymer can be selected bythe stoichiometry of the polymer synthesis. For example, when a polymeris prepared by the reaction of 4,4′-dichlorobenzophenone and bis-phenolA in the presence of potassium carbonate in N,N-dimethylacetamide, ifthe bis-phenol A is present in about 7.5 to 8 mole percent excess, theresulting polymer generally is bis-phenol A-terminated (wherein thebis-phenol A moiety may or may not have one or more hydroxy groupsthereon), and the resulting polymer typically has a polydispersity(M_(w)/M_(n)) of from about 2 to about 3.5. When the bis-phenolA-terminated polymer is subjected to further reactions to placefunctional groups thereon, such as haloalkyl groups, and/or to convertone kind of functional group, such as a haloalkyl group, to another kindof functional group, such as an unsaturated ester group, thepolydispersity of the polymer can rise to the range of from about 4 toabout 6. In contrast, if the 4,4′-dichlorobenzophenone is present inabout 7.5 to 8 mole percent excess, the reaction time is approximatelyhalf that required for the bis-phenol A excess reaction, the resultingpolymer generally is benzophenone-terminated (wherein the benzophenonemoiety may or may not have one or more chlorine atoms thereon), and theresulting polymer typically has a polydispersity of from about 2 toabout 3.5. When the benzophenone-terminated polymer is subjected tofurther reactions to place functional groups thereon, such as haloalkylgroups, and/or to convert one kind of functional group, such as ahaloalkyl group, to another kind of functional group, such as anunsaturated ester group, the polydispersity of the polymer typicallyremains in the range of from about 2 to about 3.5. Similarly, when apolymer is prepared by the reaction of 4,4′-difluorobenzophenone witheither 9,9′-bis(4-hydroxyphenyl)fluorene or bis-phenol A in the presenceof potassium carbonate in N,N-dimethylacetamide, if the4,4′-difluorobenzophenone reactant is present in excess, the resultingpolymer generally has benzophenone terminal groups (which may or may nothave one or more fluorine atoms thereon). The well-known Carothersequation can be employed to calculate the stoichiometric offset requiredto obtain the desired molecular weight. (See, for example, William H.Carothers, “An Introduction to the General Theory of CondensationPolymers,” Chem. Rev., 8, 353 (1931) and J. Amer. Chem. Soc., 51, 2548(1929); see also P. J. Flory, Principles of Polymer Chemistry, CornellUniversity Press, Ithaca, N.Y. (1953); the disclosures of each of whichare totally incorporated herein by reference.) More generally speaking,during the preparation of polymers of the formula

the stoichiometry of the polymer synthesis reaction can be adjusted sothat the end groups of the polymer are derived from the “A” groups orderived from the “B” groups. Specific functional groups can also bepresent on these terminal “A” groups or “B” groups, such as ethynylgroups or other thermally sensitive groups, hydroxy groups which areattached to the aromatic ring on an “A” or “B” group to form a phenolicmoiety, halogen atoms which are attached to the “A” or “B” group, or thelike.

Polymers with end groups derived from the “A” group, such asbenzophenone groups or halogenated benzophenone groups, may be preferredfor some applications because both the syntheses and some of thereactions of these materials to place substituents thereon may be easierto control and may yield better results with respect to, for example,cost, molecular weight, molecular weight range, and polydispersity(M_(w)/M_(n)) compared to polymers with end groups derived from the “B”group, such as bis-phenol A groups (having one or more hydroxy groups onthe aromatic rings thereof) or other phenolic groups. While not beinglimited to any particular theory, it is believed that the haloalkylationreaction in particular proceeds most rapidly on the phenolic tails whenthe polymer is bis-phenol A terminated. Moreover, it is believed thathalomethylated groups on phenolic-terminated polymers may beparticularly reactive to subsequent crosslinking or chain extension. Incontrast, it is generally believed that halomethylation does not takeplace on the terminal aromatic groups with electron withdrawingsubstituents, such as benzophenone, halogenated benzophenone, or thelike.

If desired, to reduce the amount of residual halogen in a photoresist orother composition containing the polymers of the present invention,thereby also reducing or eliminating the generation of hydrohalic acidduring a subsequent thermal curing step, any residual halogen atoms orhaloalkyl groups on the photopatternable polymer can be converted tomethoxy groups, hydroxide groups, acetoxy groups, amine groups, or thelike by any desired process, including those processes disclosedhereinabove, those disclosed in, for example, British Patent 863,702,Chem Abstr. 55, 18667b (1961), and other publications previouslyincorporated herein by reference, and the like.

The photopatternable polymer can be cured by uniform exposure to actinicradiation at wavelengths and/or energy levels capable of causingcrosslinking or chain extension of the polymer through thephotosensitivity-imparting groups. Alternatively, the photopatternablepolymer is developed by imagewise exposure of the material to radiationat a wavelength and/or at an energy level to which thephotosensitivity-imparting groups are sensitive. Typically, aphotoresist composition will contain the photopatternable polymer, anoptional solvent for the photopatternable polymer, an optionalsensitizer, and an optional photoinitiator. Solvents may be particularlydesirable when the uncrosslinked photopatternable polymer has a highT_(g). The solvent and photopatternable polymer typically are present inrelative amounts of from 0 to about 99 percent by weight solvent andfrom about 1 to 100 percent polymer, preferably are present in relativeamounts of from about 20 to about 60 percent by weight solvent and fromabout 40 to about 80 percent by weight polymer, and more preferably arepresent in relative amounts of from about 30 to about 60 percent byweight solvent and from about 40 to about 70 percent by weight polymer,although the relative amounts can be outside these ranges.

Sensitizers absorb light energy and facilitate the transfer of energy tounsaturated bonds which can then react to crosslink or chain extend theresin. Sensitizers frequently expand the useful energy wavelength rangefor photoexposure, and typically are aromatic light absorbingchromophores. Sensitizers can also lead to the formation ofphotoinitiators, which can be free radical or ionic. When present, theoptional sensitizer and the photopatternable polymer typically arepresent in relative amounts of from about 0.1 to about 20 percent byweight sensitizer and from about 80 to about 99.9 percent by weightphotopatternable polymer, and preferably are present in relative amountsof from about 1 to about 10 percent by weight sensitizer and from about90 to about 99 percent by weight photopatternable polymer, although therelative amounts can be outside these ranges.

Photoinitiators generally generate ions or free radicals which initiatepolymerization upon exposure to actinic radiation. When present, theoptional photoinitiator and the photopatternable polymer typically arepresent in relative amounts of from about 0.1 to about 20 percent byweight photoinitiator and from about 80 to about 99.9 percent by weightphotopatternable polymer, and preferably are present in relative amountsof from about 1 to about 10 percent by weight photoinitiator and fromabout 90 to about 99 percent by weight photopatternable polymer,although the relative amounts can be outside these ranges.

A single material can also function as both a sensitizer and aphotoinitiator.

Examples of specific sensitizers and photoinitiators include Michler'sketone (Aldrich Chemical Co.), Darocure 1173, Darocure 4265, Irgacure184, Irgacure 261, and Irgacure 907 (available from Ciba-Geigy, Ardsley,N.Y.), and mixtures thereof. Further background material on initiatorsis disclosed in, for example, Ober et al., J.M.S.—Pure Appl. Chem., A30(12), 877-897 (1993); G. E. Green, B. P. Stark, and S. A. Zahir,“Photocrosslinkable Resin Systems,” J. Macro. Sci.—Revs. Macro. Chem.,C21(2), 187 (1981); H. F. Gruber, “Photoinitiators for Free RadicalPolymerization,” Prog. Polym. Sci., Vol. 17, 953 (1992); Johann G.Kloosterboer, “Network Formation by Chain CrosslinkingPhotopolymerization and Its Applications in Electronics,” Advances inPolymer Science, 89, Springer-Verlag Berlin Heidelberg (1988); and“Diaryliodonium Salts as Thermal Initiators of Cationic Polymerization,”J. V. Crivello, T. P. Lockhart, and J. L. Lee, J. of Polymer Science:Polymer Chemistry Edition, 21, 97 (1983), the disclosures of each ofwhich are totally incorporated herein by reference. Sensitizers areavailable from, for example, Aldrich Chemical Co., Milwaukee, Wis., andPfaltz and Bauer, Waterberry, Conn. Benzophenone and its derivatives canfunction as photosensitizers. Triphenylsulfonium and diphenyl iodoniumsalts are examples of typical cationic photoinitiators.

Inhibitors may also optionally be present in the photoresist containingthe photopatternable polymer. Examples of suitable inhibitors includeMEHQ, a methyl ether of hydroquinone, of the formula

t-butylcatechol, of the formula

hydroquinone, of the formula

and the like, the inhibitor typically present in an amount of from about500 to about 1,500 parts per million by weight of a photoresist solutioncontaining about 40 percent by weight polymer solids, although theamount can be outside this range.

While not being limited to any particular theory, it is believed thatexposure to, for example, ultraviolet radiation generally leads tocrosslinking or chain extension at the “long” bond sites as shown belowfor the polymer having acryloyl functional groups, wherein the ethyleniclinkage in the acryloyl group is opened to form the link:

An analogous opening of the ethylenic linkage occurs for otherunsaturated groups. The alkylcarboxymethylene and ether substitutedpolymers are curable by exposure to ultraviolet light, preferably in thepresence of heat and one or more cationic initiators, such astriarylsulfonium salts, diaryliodium salts, and other initiators asdisclosed in, for example, Ober et al., J.M.S.—Pure Appl. Chem., A30(12), 877-897 (1993), the disclosure of which is totally incorporatedherein by reference. While not being limited to any particular theory,it is believed that the cationic mechanism is as shown below for themethylcarboxymethylene substituted polymer, wherein acetic acid isliberated and the “long” bond indicates the crosslinking or chainextension site:

The reaction is similar for the ether substituted polymer, except thatthe corresponding alkanol is liberated.

The photoresist containing the allyl ether substituted polymer isdeveloped by imagewise exposure of the material to radiation at awavelength to which it is sensitive. While not being limited to anyparticular theory, it is believed that exposure to, for example,ultraviolet radiation generally opens the ethylenic linkage in the allylether groups and leads to crosslinking or chain extension at the “long”bond sites as shown below:

For the epoxy-substituted polymer, while not being limited to anyparticular theory, it is believed that exposure to, for example,ultraviolet radiation generally causes generation of acidic species bythe initiator, followed by reaction of the acidic species with the epoxygroups to cause ring opening and crosslinking or chain extension at the“long” bond sites as shown below:

Amine curing of the epoxidized polymer is also possible, with curingoccurring upon the application of heat. While not being limited to anyparticular theory, it is believed that the curing scheme in one exampleis as follows:

For the halomethylated polymer, While not being limited to anyparticular theory, it is believed that exposure to, for example, e-beam,deep ultraviolet, or x-ray radiation generally results in free radicalcleavage of the halogen atom from the methyl group to form a benzylradical. Crosslinking or chain extension then occurs at the “long” bondsites as illustrated below:

For the unsaturated ammonium or unsaturated phosphonium substitutedpolymers of the present invention, while not being limited to anyparticular theory, it is believed that exposure to, for example,ultraviolet radiation generally opens the ethylenic linkage in thephotosensitivity-imparting groups and leads to crosslinking or chainextension at the “long” bond sites as shown below:

For the hydroxyalkylated, haloalkylated, and allyl-substituted polymersof the present invention, one specific example of a class of suitablesensitizers or initiators is that of bis(azides), of the general formula

wherein R is

wherein R₁, R₂, R₃, and R₄ each, independently of the others, is ahydrogen atom, an alkyl group, including saturated, unsaturated, andcyclic alkyl groups, preferably with from 1 to about 30 carbon atoms,and more preferably with from 1 to about 6 carbon atoms, a substitutedalkyl group, an aryl group, preferably with from 6 to about 18 carbonatoms, and more preferably with about 6 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 48 carbonatoms, and more preferably with from about 7 to about 8 carbon atoms, ora substituted arylalkyl group, and x is 0 or 1, wherein the substituentson the substituted alkyl, aryl, and aryl groups can be (but are notlimited to) alkyl groups, including saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 6carbon atoms, substituted alkyl groups, preferably with from 1 to about6 carbon atoms, aryl groups, preferably with from 6 to about 24 carbonatoms, substituted aryl groups, preferably with from 6 to about 24carbon atoms, arylalkyl groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, alkoxy groups, preferably with from 1 to about 6carbon atoms, substituted alkoxy groups, preferably with from 1 to about6 carbon atoms, aryloxy groups, preferably with from 6 to about 24carbon atoms, substituted aryloxy groups, preferably with from 6 toabout 24 carbon atoms, arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyloxy groups, preferably withfrom 7 to about 30 carbon atoms, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, mercapto groups, nitroso groups,sulfone groups, acyl groups, acid anhydride groups, azide groups, andthe like, wherein the substituents on the substituted alkyl groups,substituted aryl groups, substituted arylalkyl groups, substitutedalkoxy groups, substituted aryloxy groups, and substituted arylalkyloxygroups can be (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein any two or more substituents canbe joined together to form a ring. Examples of suitable bis(azides)include 4,4′-diazidostilbene, of the formula

4,4′-diazidobenzophenone, of the formula

2,6-di-(4′-azidobenzal)-4-methylcyclohexanone, of the formula

4,4′-diazidobenzalacetone, of the formula

and the like. While not being limited to any particular theory, it isbelieved that exposure to, for example, ultraviolet radiation enablescuring, as illustrated below for the hydroxymethylated polymer:

wherein X and X′ each, independently of the other, is —H or —OH (or —Hor a halogen atom in the case of the haloalkyloted polymer). Similarly,for the allyl-substituted polymer, it is believed that the curingreaction scheme is as follows:

Alternatively, a hydroxyalkylated polymer can be further reacted torender it more photosensitive. For example, a hydroxymethylated polymerof the formula

can react with isocyanato-ethyl methacrylate, of the formula

(available from Polysciences, Warrington, Pa.) to form a photoactivepolymer of the formula

This reaction can be carried out in methylene chloride at 25° C. with 1part by weight polymer, 1 part by weight isocyanato-ethyl methacrylate,and 50 parts by weight methylene chloride. Typical reaction temperaturesare from about 0 to about 50° C., with 10 to 25° C. preferred. Typicalreaction times are between about 1 and about 24 hours, with about 16hours preferred. During exposure to, for example, ultraviolet radiation,the ethylenic bond opens and crosslinking or chain extension occurs atthat site.

While not being limited to any particular theory, it is believed thatthermal cure can also lead to extraction of the hydroxy group and tocrosslinking or chain extension at the “long” bond sites as shown below:

If desired, the hydroxyalkylated polymer can be further reacted with anunsaturated acid chloride to substitute some or all of the hydroxyalkylgroups with photosensitive groups such as acryloyl or methacryloylgroups or other unsaturated ester groups. The reaction can take place inthe presence of triethylamine, which acts as a hydrochloric acidscavenger to form NEt₃H⁺Cl⁻. Examples of suitable reactants includeacryloyl chloride, methacryloyl chloride, cinnamoyl chloride, crotonoylchloride, ethacryloyl chloride, oleyl chloride, linoleyl chloride,maleoyl chloride, fumaroyl chloride, itaconoyl chloride, citraconoylchloride, acid chlorides of phenylmaleic acid, 3-hexene-1,6-dicarboxylicacid, and the like. Examples of suitable solvents include1,1,2,2-tetrachloroethane, methylene chloride, and the like. Typically,the reactants are present in relative amounts with respect to each otherby weight of about 1 part hydroxyalkylated polymer, about 1 parttriethylamine, about 30 parts solvent, and about 1 part acid chloride.

Some or all of the hydroxyalkyl groups can be replaced with unsaturatedester substituents. Longer reaction times generally lead to greaterdegrees of substitution of hydroxyalkyl groups with unsaturated estersubstituents.

Typical reaction temperatures are from about 0 to about 50° C., andpreferably from about 10 to about 25° C., although the temperature canbe outside this range. Typical reaction times are from about 1 to about24 hours, and preferably from about 5 to about 16 hours, although thetime can be outside these ranges.

The general reaction scheme, illustrated below for the hydroxymethylatedpolymer, is as follows:

wherein a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units. In the corresponding reaction withmethacryloyl chloride, the

groups are replaced with

groups.

Higher degrees of hydroxyalkylation generally lead to higher degrees ofsubstitution with unsaturated ester groups and thereby to greaterphotosensitivity of the polymer. Different degrees of substitution maybe desirable for different applications. Too high a degree ofsubstitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. Optimum amounts of unsaturated ester substitution arefrom about 0.8 to about 1.3 milliequivalents of unsaturated ester groupper gram of resin. For example, for applications wherein thephotopatternable polymer is to be used as a layer in a thermal ink jetprinthead, the degree of acryloylation (i.e., the average number ofunsaturated ester groups per monomer repeat unit) for polymers of theformula

preferably is from about 0.5 to about 1.2, and more preferably fromabout 0.65 to about 0.8, although the degree of substitution can beoutside these ranges for ink jet printhead applications.

Some or all of the hydroxyalkyl groups can be replaced with unsaturatedester substituents. Longer reaction times generally lead to greaterdegrees of substitution of hydroxyalkyl groups with unsaturated estersubstituents.

Many of the photosensitivity-imparting groups which are indicated aboveas being capable of enabling crosslinking or chain extension of thepolymer upon exposure to actinic radiation can also enable crosslinkingor chain extension of the polymer upon exposure to elevatedtemperatures; thus the polymers of the present invention can also, ifdesired, be used in applications wherein thermal curing is employed.

In all of the above reactions and substitutions illustrated above forthe polymer of the formula

it is to be understood that analogous reactions and substitutions willoccur for the polymer of the formula

In another preferred embodiment of the present invention, a photoresistis prepared which comprises a mixture of the polymer substituted withphotoactive groups, such as unsaturated ester groups, and thehalomethylated polymer. The halomethylated polymer, which can be used asan intermediate in the synthesis of the photosensitivity-imparting groupsubstituted polymer, also functions as an accelerator which generatesfree radicals upon exposure to ultraviolet light, and thus can be usedinstead of or in addition to other accelerators or sensitizers, such asMichler's ketone or the like. In addition, the substitution of thehalomethylated precursor with the photosensitivity-imparting groups canbe controlled so as to yield a mixture containing a known proportion ofthe halomethyl residue. Accordingly, a photoresist can be prepared ofthe photosensitivity-imparting group substituted polymer without theneed to add an additional initiator to the precursor material.Typically, the halomethylated polymer (which typically is substituted toa degree of from about 0.25 to about 2.0 halomethyl groups per monomerrepeat unit, preferably from about 1 to about 2 halomethyl groups permonomer repeat unit, and more preferably from about 1.5 to about 2halomethyl groups per monomer repeat unit) and thephotosensitivity-imparting group substituted polymer (which typically issubstituted to a degree of from about 0.25 to about 2.0photosensitivity-imparting groups per monomer repeat unit, preferablyfrom about 0.5 to about 1 photosensitivity-imparting group per monomerrepeat unit, and more preferably from about 0.7 to about 0.8photosensitivity-imparting group per monomer repeat unit) are present inrelative amounts such that the degree of substitution when measured forthe blended composition is from about 0.25 to about 1.5, preferably fromabout 0.5 to about 0.8, and more preferably about 0.75photosensitivity-imparting groups per monomer repeat unit, and fromabout 0.25 to about 2.25, preferably from about 0.75 to about 2, andmore preferably from about 0.75 to about 1 halomethyl group per monomerrepeat unit, although the relative amounts can be outside these ranges.Similarly, a polymer substituted with both halomethyl andphotosensitivity-imparting groups can function as an accelerator. Inthis instance, the accelerating polymer typically exhibits a degree ofsubstitution of from about 0.25 to about 1.5, preferably from about 0.5to about 0.8, and more preferably about 0.75 photosensitivity-impartinggroups per monomer repeat unit, and from about 0.25 to about 2.25,preferably from about 0.75 to about 2, and more preferably from about0.75 to about 1 halomethyl group per monomer repeat unit, although therelative amounts can be outside these ranges.

Particularly preferred as reaction accelerators are polymers of theformula

wherein A is selected so that the monomeric unit contains a benzophenonemoiety and x and B are as defined hereinabove, said polymer having atleast one halomethyl substituent per monomer repeat unit in at leastsome of the monomer repeat units of the polymer, said polymer having atleast one photosensitivity-imparting group per monomer repeat unit in atleast some of the monomer repeat units of the polymer. Examples ofsuitable A groups for this embodiment include

and the like. While not being limited to any particular theory, it isbelieved that in this embodiment, the presence of the benzophenonemoiety acts as a photoabsorbing element in the polymer backbone andcontributes to the photoinitiating characteristics of the polymer. Inthis embodiment, advantages include high sensitivity, highdevelopability, and high aspect ratios in thick films.

When the halomethylated polymer is present in relatively highconcentrations in a photoresist with respect to the amount ofphotosensitivity-imparting group substituted polymer, the halomethylatedmaterial can also act as an ultraviolet polymerization inhibitor.

The precise degree of photosensitivity-imparting group substitution ofthe polymer may be difficult to control, and different batches ofphotosensitivity-imparting group substituted polymers may have somewhatdifferent degrees of substitution even though the batches were preparedunder similar conditions. Photoresist compositions containing polymersfor which the degree of photosensitivity-imparting group substitutionvaries will exhibit variation in characteristics such as photospeed,imaging energy requirements, photosensitivity, shelf life, film formingcharacteristics, development characteristics, and the like. Accordingly,if desired, the photoresist composition can be formulated from a mixtureof (A) a first component comprising a polymer, at least some of themonomer repeat units of which have at least onephotosensitivity-imparting group thereon, said polymer having a firstdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the above general formula; and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture typically is from about 10,000to about 50,000, preferably from about 10,000 to about 35,000, and morepreferably from about 10,000 to about 25,000, although the weightaverage molecular weight of the blend can be outside these ranges; andwherein the third or fifth degree of photosensitivity-imparting groupsubstitution typically is from about 0.25 to about 2 milliequivalents ofphotosensitivity-imparting group per gram of mixture, preferably 0.8 toabout 1.4 milliequivalents of photosensitivity-imparting groups per gramof mixture, although the degree of substitution can be outside theseranges.

The first photosensitivity-imparting group substituted polymer can beprepared as described hereinabove. In one embodiment of the presentinvention, the second component is a polymer which either is substitutedwith photosensitivity-imparting groups but to a lesser degree than thefirst polymer, or which does not contain photosensitivity-impartinggroup substituents. The second polymer may be selected from a widevariety of polymers. For example, in one embodiment of the presentinvention, two different photosensitivity-imparting group substitutedpolymers are blended together, wherein one has a higher degree ofsubstitution than the other. In another embodiment of the presentinvention, the second polymer is a polymer of the above general formulabut having no photosensitivity-imparting group substituents, such as thepolymer starting materials (and, if deep ultraviolet, x-ray, or electronbeam radiation are not being used for photoexposure, the haloalkylatedpolymers prepared as described hereinabove). In yet another embodimentof the present invention, the second polymer is not necessarily apolymer of the above general formula, but is selected from any of a widevariety of other high performance polymers suitable for obtaining adesirable photoresist mixture with the desired characteristics, such asepoxies, polycarbonates, diallyl phthalates, chloromethylatedbis-fluorenones, polyphenylenes, phenoxy resins, polyarylene ethers,poly (ether imides), polyarylene ether ketones, polyphenylene sulfides,polysulfones, poly (ether sulfones), polyphenyl triazines, polyimides,polyphenyl quinoxalines, other polyheterocyclic systems, and the like,as well as mixtures thereof. High performance polymers typically aremoldable at temperatures above those at which their use is intended, andare useful for high temperature structural applications. While most highperformance polymers are thermoplastic, some, such as phenolics, tend tobe thermosetting. Any combination of photosensitivity-imparting groupsubstituted polymers of the above formula, polymers having nophotosensitivity-imparting group substituents but falling within theabove general formula, and/or other polymers outside the scope of theabove general formula can be used as the second polymer for the presentinvention. For example, in one embodiment of the present invention, aphotoresist is prepared from: (a) 60 parts by weight of a polyaryleneether ketone within the above general formula having 1 chloromethylgroup per repeating monomer unit, 1 acrylate group per repeating monomerunit, and a number average molecular weight of 60,000; (b) 40 parts byweight of a polyarylene ether ketone resin within the above generalformula but having no substituents thereon, with a number averagemolecular weight of 2,800 and a polydispersity (M_(w)/M_(n)) of about2.5; and (c) 10 parts by weight of EPON 1001 adhesive resin (ShellChemical Company, Houston, Tex.). This mixture has a degree ofacryloylation of about 1.1 milliequivalents of acrylate per gram ofresin solids and a weight average molecular weight of 34,000. Typically,when a photoresist is prepared from a mixture of an unsaturated estersubstituted polymer of the above general formula and a second polymerhaving no unsaturated ester groups, a photoresist solution containingabout 40 percent by weight polymer solids will contain from 10 to about25 parts by weight of a polymer having unsaturated ester substituentsand from about 10 to about 25 parts by weight of a polymer having nounsaturated ester substituents.

Alternatively, the second component can be a reactive diluent. In someembodiments, the reactive diluent is a liquid, and can replace a solventwhen the photopatternable polymer is too high in viscosity to be curedwithout solvents. In other embodiments, the reactive diluent is a solid.The reactive diluent has functional groups which are capable ofpolymerizing when the reactive diluent is exposed to actinic radiationat an energy or wavelength level which is capable of inducingcrosslinking or chain extension in the photopatternable polymer.Reactive diluents preferably are monomeric or oligomeric, and include(but are not limited to) mono-, di-, tri-, and multi-functionalunsaturated ester monomers and the like. Examples of suitable reactivediluents include monoacrylates, such as cyclohexyl acrylate, 2-ethoxyethyl acrylate, 2-methoxy ethyl acrylate, 2(2-ethoxyethoxy) ethylacrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, octyl acrylate,lauryl acrylate, behenyl acrylate, 2-phenoxy ethyl acrylate, tertiarybutyl acrylate, glycidyl acrylate, isodecyl acrylate, benzyl acrylate,hexyl acrylate, isooctyl acrylate, isobornyl acrylate, butanediolmonoacrylate, ethoxylated phenol monoacrylate, oxyethylated phenolacrylate, monomethoxy hexanediol acrylate, β-carboxy ethyl acrylate,dicyclopentyl acrylate, carbonyl acrylate, octyl decyl acrylate,ethoxylated nonylphenol acrylate, hydroxyethyl acrylate, hydroxyethylmethacrylate, and the like, diacrylates, such as 1,3-butylene glycoldiacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate,1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, triethyleneglycol diacrylate, tripropylene glycol diacrylate, polybutanedioldiacrylate, polyethylene glycol diacrylate, propoxylated neopentylglycol diacrylate, ethoxylated neopentyl glycol diacrylate,polybutadiene diacrylate, and the like, polyacrylates, such astrimethylol propane triacrylate, pentaerythritol tetraacrylale,pentaerythritol triacrylate, dipentaerythritol pentaacrylate, glycerolpropoxy triacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate,pentaacrylate ester, and the like, epoxy acrylates, polyester acrylates,polyether polyol acrylates, urethane acrylates, amine acrylates, acrylicacrylates, and the like. Mixtures of two or more materials can also beemployed as the reactive diluent. Suitable reactive diluents arecommercially available from, for example, Sartomer Co., Inc., HenkelCorp., Radcure Specialties, and the like. When the second component is areactive diluent, typically, the first and second components are presentin relative amounts of from about 5 to about 50 percent by weightreactive diluent (second component) and from about 50 to about 95percent by weight polymer (first component), and preferably in relativeamounts of from about 10 to about 20 percent by weight reactive diluent(second component) and from about 80 to about 90 percent by weightpolymer (first component), although the relative amounts can be outsidethese ranges.

If desired, to reduce the amount of residual halogen in a photoresist orother composition containing the polymers of the present invention,thereby also reducing or eliminating the generation of hydrohalic acidduring a subsequent thermal curing step, any residual haloalkyl groupson the photopatternable polymer can be converted to methoxy groups,hydroxide groups, acetoxy groups, amine groups, or the like by anydesired process, including those processes disclosed hereinabove, thosedisclosed in, for example, British Patent 863,702, Chem Abstr. 55,18667b (1961), and other publications previously incorporated herein byreference, and the like.

Photopatternable polymeric materials of the present invention can beused as components in ink jet printheads. The printheads of the presentinvention can be of any suitable configuration. An example of a suitableconfiguration, suitable in this instance for thermal ink jet printing,is illustrated schematically in FIG. 1, which depicts an enlarged,schematic isometric view of the front face 29 of a printhead 10 showingthe array of droplet emitting nozzles 27. Referring also to FIG. 2,discussed later, the lower electrically insulating substrate or heatingelement plate 28 has the heating elements 34 and addressing electrodes33 patterned on surface 30 thereof, while the upper substrate or channelplate 31 has parallel grooves 20 which extend in one direction andpenetrate through the upper substrate front face edge 29. The other endof grooves 20 terminate at slanted wall 21, the floor 41 of the internalrecess 24 which is used as the ink supply manifold for the capillaryfilled ink channels 20, has an opening 25 therethrough for use as an inkfill hole. The surface of the channel plate with the grooves are alignedand bonded to the heater plate 28, so that a respective one of theplurality of hearing elements 34 is positioned in each channel, formedby the grooves and the lower substrate or heater plate. Ink enters themanifold formed by the recess 24 and the lower substrate 28 through thefill hole 25 and by capillary action, fills the channels 20 by flowingthrough an elongated recess 38 formed in the thick film insulative layer18. The ink at each nozzle forms a meniscus, the surface tension ofwhich prevents the ink from weeping therefrom. The addressing electrodes33 on the lower substrate or channel plate 28 terminate at terminals 32.The upper substrate or channel plate 31 is smaller than that of thelower substrate in order that the electrode terminals 32 are exposed andavailable for wire bonding to the electrodes on the daughter board 19,on which the printhead 10 is permanently mounted. Layer 18 is a thickfilm passivation layer, discussed later, sandwiched between the upperand lower substrates. This layer is etched to expose the heatingelements, thus placing them in a pit, and is etched to form theelongated recess to enable ink flow between the manifold 24 and the inkchannels 20. In addition, the thick film insulative layer is etched toexpose the electrode terminals.

A cross sectional view of FIG. 1 is taken along view line 2—2 throughone channel and shown as FIG. 2 to show how the ink flows from themanifold 24 and around the end 21 of the groove 20 as depicted by arrow23. As is disclosed in U.S. Pat. No. 4,638,337, U.S. Pat. No. 4,601,777,and U.S. Pat. No. Re. 32,572, the disclosures of each of which aretotally incorporated herein by reference, a plurality of sets of bubblegenerating heating elements 34 and their addressing electrodes 33 can bepatterned on the polished surface of a single side polished (100)silicon wafer. Prior to patterning, the multiple sets of printheadelectrodes 33, the resistive material that serves as the heatingelements 34, and the common return 35, the polished surface of the waferis coated with an underglaze layer 39 such as silicon dioxide, having atypical thickness of from about 5,000 Angstroms to about 2 microns,although the thickness can be outside this range. The resistive materialcan be a doped polycrystalline silicon, which can be deposited bychemical vapor deposition (CVD) or any other well known resistivematerial such as zirconium boride (ZrB₂). The common return and theaddressing electrodes are typically aluminum leads deposited on theunderglaze and over the edges of the heating elements. The common returnends or terminals 37 and addressing electrode terminals 32 arepositioned at predetermined locations to allow clearance for wirebonding to the electrodes (not shown) of the daughter board 19, afterthe channel plate 31 is attached to make a printhead. The common return35 and the addressing electrodes 33 are deposited to a thicknesstypically of from about 0.5 to about 3 microns, although the thicknesscan be outside this range, with the preferred thickness being 1.5microns.

If polysilicon heating elements are used, they may be subsequentlyoxidized in steam or oxygen at a relatively high temperature, typicallyabout 1,100° C. although the temperature can be above or below thisvalue, for a period of time typically of from about 50 to about 80minutes, although the time period can be outside this range, prior tothe deposition of the aluminum leads, in order to convert a smallportion of the polysilicon to SiO₂. In such cases, the heating elementsare thermally oxidized to achieve an overglaze (not shown) of SiO₂ witha thickness typically of from about 500 Angstroms to about 1 micron,although the thickness can be outside this range, which has goodintegrity with substantially no pinholes.

In one embodiment, polysilicon heating elements are used and an optionalsilicon dioxide thermal oxide layer 17 is grown from the polysilicon inhigh temperature steam. The thermal oxide layer is typically grown to athickness of from about 0.5 to about 1 micron, although the thicknesscan be outside this range, to protect and insulate the heating elementsfrom the conductive ink. The thermal oxide is removed at the edges ofthe polysilicon heating elements for attachment of the addressingelectrodes and common return, which are then patterned and deposited. Ifa resistive material such as zirconium boride is used for the heatingelements, then other suitable well known insulative materials can beused for the protective layer thereover. Before electrode passivation, atantalum (Ta) layer (not shown) can be optionally deposited, typicallyto a thickness of about 1 micron, although the thickness can be above orbelow this value, on the heating element protective layer 17 for addedprotection thereof against the cavitational forces generated by thecollapsing ink vapor bubbles during printhead operation. The tantalumlayer is etched off all but the protective layer 17 directly over theheating elements using, for example, CF₄/O₂ plasma etching. Forpolysilicon heating elements, the aluminum common return and addressingelectrodes typically are deposited on the underglaze layer and over theopposing edges of the polysilicon heating elements which have beencleared of oxide for the attachment of the common return and electrodes.

For electrode passivation, a film 16 is deposited over the entire wafersurface, including the plurality of sets of heating elements andaddressing electrodes. The passivation film 16 provides an ion barrierwhich will protect the exposed electrodes from the ink. Examples ofsuitable ion barrier materials for passivation film 16 includepolyimide, plasma nitride, phosphorous doped silicon dioxide, materialsdisclosed hereinafter as being suitable for insulative layer 18, and thelike, as well as any combinations thereof. An effective ion barrierlayer is generally achieved when its thickness is from about 1000Angstroms to about 10 microns, although the thickness can be outsidethis range. In 300 dpi printheads, passivation layer 16 preferably has athickness of about 3 microns, although the thickness can be above orbelow this value. In 600 dpi printheads, the thickness of passivationlayer 16 preferably is such that the combined thickness of layer 16 andlayer 18 is about 25 microns, although the thickness can be above orbelow this value. The possivation film or layer 16 is etched off of theterminal ends of the common return and addressing electrodes for wirebonding later with the daughter board electrodes. This etching of thesilicon dioxide film can be by either the wet or dry etching method.Alternatively, the electrode passivation can be by plasma depositedsilicon nitride (Si₃N₄).

Next, a thick film type insulative layer 18, of a material to bediscussed in further detail hereinbelow, is formed on the passivationlayer 16, typically having a thickness of from about 10 to about 100microns and preferably in the range of from about 25 to about 50microns, although the thickness can be outside these ranges. Even morepreferably, in 300 dpi printheads, layer 18 preferably has a thicknessof about 30 microns, and in 600 dpi printheads, layer 18 preferably hasa thickness of from about 20 to about 22 microns, although otherthicknesses can be employed. The insulative layer 18 isphotolithographically processed to enable etching and removal of thoseportions of the layer 18 over each heating element (forming recesses26), the elongated recess 38 for providing ink passage from the manifold24 to the ink channels 20, and over each electrode terminal 32, 37. Theelongated recess 38 is formed by the removal of this portion of thethick film layer 18. Thus, the passivation layer 16 alone protects theelectrodes 33 from exposure to the ink in this elongated recess 38.

FIG. 3 is a similar view to that of FIG. 2 with a shallowanisotropically etched groove 40 in the heater plate, which is silicon,prior to formation of the underglaze 39 and patterning of the heatingelements 34, electrodes 33 and common return 35. This recess 40 permitsthe use of only the thick film insulative layer 18 and eliminates theneed for the usual electrode passivating layer 16. Since the thick filmlayer 18 is impervious to water and relatively thick (typically fromabout 20 to about 40 microns, although the thickness can be outside thisrange), contamination introduced into the circuitry will be much lessthan with only the relatively thin passivation layer 16 well known inthe art. The heater plate is a fairly hostile environment for integratedcircuits. Commercial ink generally entails a low attention to purity. Asa result, the active part of the heater plate will be at elevatedtemperature adjacent to a contaminated aqueous ink solution whichundoubtedly abounds with mobile ions. In addition, it is generallydesirable to run the heater plate at a voltage of from about 30 to about50 volts, so that there will be a substantial field present. Thus, thethick film insulative layer 18 provides improved protection for theactive devices and provides improved protection, resulting in longeroperating lifetime for the heater plate.

When a plurality of lower substrates 28 are produced from a singlesilicon wafer, at a convenient point after the underglaze is deposited,at least two alignment markings (not shown) preferably arephotolithographically produced at predetermined locations on the lowersubstrates 28 which make up the silicon wafer. These alignment markingsare used for alignment of the plurality of upper substrates 31containing the ink channels. The surface of the single sided wafercontaining the plurality of sets of heating elements is bonded to thesurface of the wafer containing the plurality of ink channel containingupper substrates subsequent to alignment.

As disclosed in U.S. Pat. No. 4,601,777 and U.S. Pat. No. 4,638,337, thedisclosures of each of which are totally incorporated herein byreference, the channel plate is formed from a two side polished, (100)silicon wafer to produce a plurality of upper substrates 31 for theprinthead. After the wafer is chemically cleaned, a pyrolytic CVDsilicon nitride layer (not shown) is deposited on both sides. Usingconventional photolithography, a via for fill hole 25 for each of theplurality of channel plates 31 and at least two vias for alignmentopenings (not shown) at predetermined locations are printed on one waferside. The silicon nitride is plasma etched off of the patterned viasrepresenting the fill holes and alignment openings. A potassiumhydroxide (KOH) anisotropic etch can be used to etch the fill holes andalignment openings. In this case, the [111] planes of the (100) wafertypically make an angle of about 54.7 degrees with the surface of thewafer. The fill holes are small square surface patterns, generally ofabout 20 mils (500 microns) per side, although the dimensions can beabove or below this value, and the alignment openings are from about 60to about 80 mils (1.5 to 3 millimeters) square, although the dimensionscan be outside this range. Thus, the alignment openings are etchedentirely through the 20 mil (0.5 millimeter) thick wafer, while the fillholes are etched to a terminating apex at about halfway through tothree-quarters through the wafer. The relatively small square fill holeis invariant to further size increase with continued etching so that theetching of the alignment openings and fill holes are not significantlytime constrained.

Next, the opposite side of the wafer is photolithographically patterned,using the previously etched alignment holes as a reference to form therelatively large rectangular recesses 24 and sets of elongated, parallelchannel recesses that will eventually become the ink manifolds andchannels of the printheads. The surface 22 of the wafer containing themanifold and channel recesses are portions of the original wafer surface(covered by a silicon nitride layer) on which an adhesive, such as athermosetting epoxy, will be applied later for bonding it to thesubstrate containing the plurality of sets of heating elements. Theadhesive is applied in a manner such that it does not run or spread intothe grooves or other recesses. The alignment markings can be used with,for example, a vacuum chuck mask aligner to align the channel wafer onthe heating element and addressing electrode wafer. The two wafers areaccurately mated and can be tacked together by partial curing of theadhesive. Alternatively, the heating element and channel wafers can begiven precisely diced edges and then manually or automatically alignedin a precision jig. Alignment can also be performed with an infraredaligner-bonder, with an infrared microscope using infrared opaquemarkings on each wafer to be aligned, or the like. The two wafers canthen be cured in an oven or laminator to bond them together permanently.The channel wafer can then be milled to produce individual uppersubstrates. A final dicing cut, which produces end face 29, opens oneend of the elongated groove 20 producing nozzles 27. The other ends ofthe channel groove 20 remain closed by end 21. However, the alignmentand bonding of the channel plate to the heater plate places the ends 21of channels 20 directly over elongated recess 38 in the thick filminsulative layer 18 as shown in FIG. 2 or directly above the recess 40as shown in FIG. 3 enabling the flow of ink into the channels from themanifold as depicted by arrows 23. The plurality of individualprintheads produced by the final dicing are bonded to the daughter boardand the printhead electrode terminals are wire bonded to the daughterboard electrodes.

In one embodiment, a heater wafer with a phosphosilicate glass layer isspin coated with a solution of Z6020 adhesion promoter (0.01 weightpercent in 95 parts methanol and 5 parts water, Dow Corning) at 3000revolutions per minute for 10 seconds and dried at 100° C. for between 2and 10 minutes. The wafer is then allowed to cool at 25° C. for 5minutes before spin coating the photoresist containing thephotopatternable polymer onto the wafer at between 1,000 and 3,000revolutions per minute for between 30 and 60 seconds. The photoresistsolution is made by dissolving polyarylene ether ketone with 0.75acryloyl groups and 0.75 chloromethyl groups per repeat unit and aweight average molecular weight of 25,000 in N-methylpyrrolidinone at 40weight percent solids with Michler's ketone (1.2 parts ketone per every10 parts of 40 weight percent solids polymer solution). The film isheated (soft baked) in an oven for between 10 and 15 minutes at 70° C.After cooling to 25° C. over 5 minutes, the film is covered with a maskand exposed to 365 nanometer ultraviolet light, amounting to between 150and 1500 milliJoules per cm². The exposed wafer is then heated at 70° C.for 2 minutes post exposure bake, followed by cooling to 25° C. over 5minutes. The film is developed with 60:40 chloroform/cyclohexanonedeveloper, washed with 90:10 hexanes/cyclohexanone, and then dried at70° C. for 2 minutes. A second developer/wash cycle is carried out ifnecessary to obtain a wafer with clean features. The processed wafer istransferred to an oven at 25° C., and the oven temperature is raisedfrom 25 to 90° C. at 2° C. per minute. The temperature is maintained at90° C. for 2 hours, and then increased to 260° C. at 2° C. per minute.The oven temperature is maintained at 260° C. for 2 hours and then theoven is turned off and the temperature is allowed to cool gradually to25° C. When thermal cure of the photoresist films is carried out underan inert atmosphere, such as nitrogen or one of the noble gases, such asargon, neon, krypton, xenon, or the like, there is markedly reducedoxidation of the developed film and improved thermal and hydrolyticstability of the resultant devices. Moreover, adhesion of developedphotoresist film is improved to the underlying substrate. If a secondlayer is spin coated over the first layer, the heat cure of the firstdeveloped layer can be stopped between 80 and 260° C. before the secondlayer is spin coated onto the first layer. A second thicker layer isdeposited by repeating the above procedure a second time. This processis intended to be a guide in that procedures can be outside thespecified conditions depending on film thickness and photoresistmolecular weight. Films at 30 microns have been developed with cleanfeatures at 600 dots per inch.

For best results with respect to well-resolved features and high aspectratios, photoresist compositions of the present invention are free ofparticulates prior to coating onto substrates. In one preferredembodiment, the photoresist composition containing the photopatternablepolymer is subjected to filtration through a 2 micron nylon filter cloth(available from Tetko). The photoresist solution is filtered through thecloth under yellow light or in the dark as a solution containing fromabout 30 to about 60 percent by weight solids using compressed air (upto about 60 psi) and a pressure filtration funnel. No dilution of thephotoresist solution is required, and concentrations of an inhibitor(such as, for example, MEHQ) can be as low as, for example, 500 partsper million or less by weight without affecting shelf life. No build inmolecular weight of the photopatternable polymer is observed during thisfiltration process. While not being limited to any particular theory, itis believed that in some instances, such as those when unsaturated estergroups are present on the photopolymerizable polymer, compressed airyields results superior to those obtainable with inert atmospherebecause oxygen in the compressed air acts as an effective inhibitor forthe free radical polymerization of unsaturated ester groups such asacrylates and methacrylates.

In a particularly preferred embodiment, the photopatternable polymer isadmixed with an epoxy resin in relative amounts of from about 75 partsby weight photopatternable polymer and about 25 parts by weight epoxyresin to about 90 parts by weight photopatternable polymer and about 10parts by weight epoxy resin. Examples of suitable epoxy resins includeEPON 1001F, available from Shell Chemical Co., Houston, Tex., believedto be of the formula

and the like, as well as mixtures thereof. Curing agents such as the “Y”curative (meta-phenylenediamine) and the like, as well as mixturesthereof, can be used to cure the epoxy resin at typical relative amountsof about 10 weight percent curative per gram of epoxy resin solids.Process conditions for the epoxy resin blended with the photopatternablepolymer are generally similar to those used to process the photoresistwithout epoxy resin. Preferably, the epoxy or epoxy blend is selected sothat its curing conditions are different from the conditions employed toapply, image, develop, and cure the photopatternable polymer. Selectivestepwise curing allows development of the photoresist film before curingthe epoxy resin to prevent unwonted epoxy residues on the device.Incorporation of the epoxy resin into the photopatternable polymermaterial improves the adhesion of the photopatternable layer to theheater plate. Subsequent to imaging and during cure of thephotopatternable polymer, the epoxy reacts with the heater layer to formstrong chemical bonds with that layer, improving adhesive strength andsolvent resistance of the interface. The presence of the epoxy may alsoimprove the hydrophilicity of the photopatternable polymer and thus mayimprove the wetting properties of the layer, thereby improving therefill characteristics of the printhead.

The printhead illustrated in FIGS. 1 through 3 constitutes a specificembodiment of the present invention. Any other suitable printheadconfiguration comprising ink-bearing channels terminating in nozzles onthe printhead surface can also be employed with the materials disclosedherein to form a printhead of the present invention.

The present invention also encompasses printing processes withprintheads according to the present invention. One embodiment of thepresent invention is directed to an ink jet printing process whichcomprises (1) providing an ink jet printhead comprising a plurality ofchannels, wherein the channels are capable of being filled with ink froman ink supply and wherein the channels terminate in nozzles on onesurface of the printhead, said printhead comprising (i) an uppersubstrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles, (ii) alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes formed thereon, and (iii) a thickfilm layer deposited on the surface of the lower substrate and over theheating elements and addressing electrodes and patterned to formrecesses therethrough to expose the heating elements and terminal endsof the addressing electrodes, said thick film layer comprising acrosslinked or chain extended photopatternable polymer of the formulaindicated hereinabove, the upper and lower substrates being aligned,mated, and bonded together to form the printhead with the grooves in theupper substrate being aligned with the heating elements in the lowersubstrate to form droplet emitting nozzles; (2) filling the channelswith an ink; and (3) causing droplets of ink to be expelled from thenozzles onto a receiver sheet in an image pattern. A specific embodimentof this process is directed to a thermal ink jet printing process,wherein the droplets of ink are caused to be expelled from the nozzlesby heating selected channels in an image pattern. The droplets can beexpelled onto any suitable receiver sheet, such as fabric, plain papersuch as Xerox® 4024 or 4010, coated papers, transparency materials, orthe like.

Specific embodiments of the invention will now be described in detail.These examples are intended to be illustrative, and the invention is notlimited to the materials, conditions, or process parameters set forth inthese embodiments. All parts and percentages are by weight unlessotherwise indicated.

EXAMPLE I

A polyarylene ether ketone of the formula

wherein n is between about 6 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 1 liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 50 grams), bis-phenol A (Aldrich 23,965-8, 48.96grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 175° C. with continuous stirring, an aliquot of thereaction product that had been precipitated into methanol was analyzedby gel pormeation chromatography (gpc) (elution solvent wastetrahydrofuran) with the following results: M_(n) 4464, M_(peak) 7583,M_(w) 7927, M_(z) 12,331, and M_(z+1) 16,980. After 48 hours at 175° C.with continuous stirring, the reaction mixture was filtered to removepotassium carbonate and precipitated into methanol (2 gallons). Thepolymer (poly(4-CPK-BPA)) was isolated in 86% yield after filtration anddrying in vacuo. GPC analysis was as follows: M_(n) 5347, M_(peak)16,126, M_(w) 15,596, M_(z) 29,209, and M_(z+1) 42,710. The glasstransition temperature of the polymer was about 120±10° C. as determinedusing differential scanning calorimetry at a heating rate of 20° C. perminute. Solution cast films from methylene chloride were clear, tough,and flexible. As a result of the stoichiometries used in the reaction,it is believed that this polymer had end groups derived from bis-phenolA.

EXAMPLE II

A polyarylene ether ketone of the formula

wherein n is between about 2 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 5 liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 48hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove insoluble salts, and the resultantsolution was added to methanol (5 gallons) to precipitate the polymer.The polymer was isolated by filtration, and the wet filter cake waswashed with water (3 gallons) and then with methanol (3 gallons). Theyield was 360 grams of vacuum dried product. The molecular weight of thepolymer was determined by gel permeation chromatography (gpc) (elutionsolvent was tetrahydrofuran) with the following results: M_(n) 3,601,M_(peak) 5,377, M_(w) 4,311, M_(z) 8,702, and M_(z+1) 12,951. The glasstransition temperature of the polymer was between 125 and 155° C. asdetermined using differential scanning calorimetry at a heating rate of20° C. per minute dependent on molecular weight. Solution cast filmsfrom methylene chloride were clear, tough, and flexible. As a result ofthe stoichiometries used in the reaction, it is believed that thispolymer had end groups derived from bis-phenol A.

EXAMPLE III

Poly(4-CPK-BPA) prepared as described in Example I (10 grams) in1,1,2,2-tetrachloroethane (100 milliliters, 161.9 grams),paraformaldehyde (5 grams), p-toluene-sulfonic acid monohydrate 1 gram),acrylic acid (15.8 grams), and crushed 4-methoxy-phenol (MEHQ, 0.2 gram)were charged in a 6.5 fluid ounce beverage bottle equipped with amagnetic stirrer. The bottle was stoppered with a rubber septum and wasthen heated to 105° C. in a silicone oil bath under argon using a needleinlet. The argon needle inlet was removed when the oil bath achieved 90°C. Heating at 105° C. was continued with constant magnetic stirring for1.5 hours. More MEHQ (0.2 grams) in 1 milliliter of1,1,2,2-tetrachloroethane was then added by syringe, and heating at 105°C. with stirring was continued for 1.5 hours longer. The reactionmixture was initially a cloudy suspension which became clear on heating.The reaction vessel was immersed as much as possible in the hot oil bathto prevent condensation of paraformaldehyde onto cooler surfaces of thereaction vessel. The reaction mixture was allowed to return to 25° C.and was then filtered through a 25 to 50 micron sintered glass Buchnerfunnel. The reaction solution was added to methanol (1 gallon) toprecipitate the polymer designated poly(acryloylmethyl-4-CPK-BPA), ofthe formula

wherein n is between about 6 and about 50. ¹H NMR spectrometry was usedto identify approximately 1 acryloylmethyl group for every four monomer(4-CPK-BPA) repeat units (i.e., a degree of acryloylation of 0.25). Thepoly(acryloylmethyl-4-CPK-BPA) was then dissolved in methylene chlorideand reprecipitated into methanol (1 gallon) to yield 10 grams of fluffywhite solid. The polymer was soluble in chlorinated solvents and polaraprotic solvents, but insoluble in acetone and alcohols. Films of thepolymer were thermally ramp cured at 0.2° C. per minute until 250° C.was achieved, and then maintained at 250° C. for 3 hours longer beforethe films were allowed to cool to 25° C. The crosslinked films wereresistant to all the thermal ink jet inks tested.

Photoactive compositions were made by preparing a 50 weight percentsolids solution in N-methyl pyrrolidone using excess methylene chlorideas a volatile diluent (to facilitate filtration of the solution througha 10 micron filter) which was later removed. Michler's ketone, of theformula

was added to the formulation at between 0.5 and 1 weight percent of theresin solids. The solution was filtered and the methylene chloride wasremoved using a rotary evaporator. Solutions at approximately 37 weightpercent solids were used to cast 30 micron dried films of the polymeronto silicon wafers which had previously been treated with a silaneadhesion promoter and heated at 70° C. for 10 minutes. The wet filmswere dried at 80° C. for 20 minutes before exposure to ultravioletlight. Ideal exposure conditions were about 2,500 milliJoules/cm². Afterexposure, the films were heated to 80° C. for 5 minutes beforedevelopment with 1:1 N-methylpyrrolidinone and cyclohexanone using aspin developer followed by a methanol wash. Thick 20 micron films couldbe developed at 300 dots per inch resolution. The heat cured films wereresistant to typical thermal ink jet ink solvents such as sulfolane andethylene glycol.

EXAMPLE IV

A solution of chloromethyl ether in methyl acetate was made by adding282.68 grams (256 milliliters) of acetyl chloride to a mixture ofdimethoxy methane (313.6 grams, 366.8 milliliters) and methanol (10milliliters) in a 5 liter 3-neck round-bottom flask equipped with amechanical stirrer, argon inlet, reflux condenser, and addition funnel.The solution was diluted with 1,066.8 milliliters of1,1,2,2-tetrachloroethane and then tin tetrachloride (2.4 milliliters)was added via a gas-tight syringe along with 1,1,2,2-tetrachloroethane(133.2 milliliters) using an addition funnel. The reaction solution washeated to 500° C. Thereafter, a solution of poly(4-CPK-BPA) prepared asdescribed in Example II (160.8 grams) in 1,000 milliliters oftetrachloroethane was added rapidly. The reaction mixture was thenheated to reflux with an oil bath set at 110° C. After four hours refluxwith continuous stirring, heating was discontinued and the mixture wasallowed to cool to 25° C. The reaction mixture was transferred in stagesto a 2 liter round bottom flask and concentrated using a rotaryevaporator with gentle heating up to 50° C. while reduced pressure wasmaintained with a vacuum pump trapped with liquid nitrogen. Theconcentrate was added to methanol (4 gallons) to precipitate the polymerusing a Waring blender. The polymer was isolated by filtration andvacuum dried to yield 200 grams of poly(4-CPK-BPA) with 1.5 chloromethylgroups per repeat unit as identified using ¹H NMR spectroscopy. When thesame reaction was carried out for 1, 2, 3, and 4 hours, the amount ofchloromethyl groups per repeat unit was 0.76, 1.09, 1.294, and 1.496,respectively.

Solvent free polymer was obtained by reprecipitation of the polymer (75grams) in methylene chloride (500 grams) into methanol (3 gallons)followed by filtration and vacuum drying to yield 70.5 grams (99.6%theoretical yield) of solvent free polymer.

When the reaction was carried out under similar conditions except that80.4 grams of poly(4-CPK-BPA) was used instead of 160.8 grams and theamounts of the other reagents were the same as indicated above, thepolymer is formed with 1.31, 1.50, 1.75, and 2 chloromethyl groups perrepeat unit in 1, 2, 3, and 4 hours, respectively, at 111° C. (oil bathtemperature).

When 241.2 grams of poly(4-CPK-BPA) was used instead of 160.8 grams withthe other reagents fixed, poly(CPK-BPA) was formed with 0.79, 0.90,0.98, 1.06, 1.22, and 1.38 chloromethyl groups per repeat unit in 1, 2,3, 4, 5, and 6 hours, respectively, at 110° C. (oil bath temperature).

When 321.6 grams of poly(4-CPK-BPA) was used instead of 160.8 grams withthe other reagents fixed, poly(CPK-BPA) was formed with 0.53, 0.59,0.64, 0.67, 0.77, 0.86, 0.90, and 0.97 chloromethyl groups per repeatunit in 1, 2, 3, 4, 5, 6, 7, and 8 hours, respectively, at 110° C. (oilbath temperature).

EXAMPLE V

A polyarylene ether ketone of the formula

was prepared as described in Example I. A solution of chloromethyl etherin methyl acetate was made by adding 35.3 grams of acetyl chloride to amixture of dimethoxy methane (45 milliliters) and methanol (1.25milliliters) in a 500 milliliter 3-neck round-bottom flask equipped witha mechanical stirrer, argon inlet, reflux condenser, and additionfunnel. The solution was diluted with 150 milliliters of1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3 milliliters)was added via syringe. The solution was heated to reflux with an oilbath set at 110° C. Thereafter, a solution of poly(4-CPK-BPA) (10 grams)in 125 milliliters of 1,1,2,2-tetrachloroethane was added over 8minutes. After two hours reflux with continuous stirring, heating wasdiscontinued and the mixture was allowed to cool to 25° C. The reactionmixture was transferred to a rotary evaporator with gentle heating atbetween 50 and 55° C. After 1 hour, when most of the volatiles had beenremoved, the reaction mixture was added to methanol (each 25 millilitersof solution was added to 0.75 liter of methanol) to precipitate thepolymer using a Waring blender. The precipitated polymer was collectedby filtration, washed with methanol, and air-dried to yield 13 grams ofoff-white powder. The polymer had about 1.5 CH₂Cl groups per repeatunit.

EXAMPLE VI

A solution was prepared containing 90 grams of a chloromethylatedpolymer prepared as described in Example IV with 1.5 chloromethyl groupsper repeat unit in 639 milliliters (558.5 grams) ofN,N-dimethylacetamide and the solution was magnetically stirred at 25°C. with sodium acrylate (51.39 grams) for 1 week. The reaction mixturewas then centrifuged, and the supernate was added to methanol (4.8gallons) using a Waring blender in relative amounts of 25 milliliters ofpolymer solution per 0.75 liter of methanol. The white powder thatprecipitated was filtered, and the wet filter cake was washed with water(3 gallons) and then methanol (3 gallons). The polymer was then isolatedby filtration and vacuum dried to yield 73.3 grams of a white powder.The polymer had 3 acrylate groups for every 4 repeating monomer unitsand 3 chloromethyl groups for every 4 repeating monomer units and aweight average molecular weight of about 25,000.

When the reaction was repeated with poly(4-CPK-BPA) with 2 chloromethylgroups per repeat unit and the other reagents remained the same, thereaction took four days to achieve 0.76 acrylate groups per repeat unitand 1.24 chloromethyl groups per repeat unit.

When the reaction was repeated with poly(4-CPK-BPA) with 1.0chloromethyl groups per repeat unit and the other reagents remained thesame, the reaction took 14-days to achieve 0.75 acrylate groups perrepeat unit and 2.5 chloromethyl groups per repeat unit.

Thick films at 30 microns were patterned at 600 dots per inchresolution. The cured films were resistant to typical thermal ink jetsolvents. Best resolutions for 30 micron films at 600 dots per inch wereachieved when the photoactive acryloylated polyarylene ether ketone hadabout 0.75 acrylates per repeat unit and between 0.75 and 1.25chloromethyl groups per repeat unit, and when the weight averagemolecular weight as determined by gel permeation chromatography wasbetween 15,000 and 25,000.

EXAMPLE VII

A chloromethylated polyarylene ether ketone having 1.5 chloromethylgroups per repeat unit was prepared as described in Example IV. Asolution containing 10 grams of the chloromethylated polymer in 71milliliters of N,N-dimethyl acetamide was magnetically stirred with 5.71grams of sodium acetate (obtained from Aldrich Chemical Co., Milwaukee,Wis.). The reaction was allowed to proceed for one week. The reactionmixture was then centrifuged and the supernate was added to methanol(0.5 gallon) to precipitate the polymer. The polymer was then filtered,washed with water (2 liters), and subsequently washed with methanol (0.5gallon). Approximately half of the chlorine atoms on the chloromethylgroups were replaced with methylcarboxymethylene groups, and it isbelieved that the polymer was of the formula

When the process was repeated under similar conditions but allowed toproceed for about 2 weeks, nearly all of the chlorine atoms on thechloromethyl groups were replaced with methylcarboxymethylene groups,and the resulting polymer was believed to be of the formula

EXAMPLE VI

The process of Example VII was repeated except that the 5.71 grams ofsodium acetate were replaced with 5.71 grams of sodium methoxide(obtained from Aldrich Chemical Co., Milwaukee, Wis.). After about twohours, approximately half of the chlorine atoms on the chloromethylgroups were replaced with methoxy groups, and it is believed that thepolymer was of the formula

When the process was repeated under similar conditions but allowed toproceed for about 2 weeks, nearly all of the chlorine atoms on thechloromethyl groups were replaced with methoxy groups, and the resultingpolymer was believed to be of the formula

EXAMPLE IX

An acryloylated polyarylene ether ketone having 0.75 chloromethyl groupsper monomer repeat unit and 0.75 acryloyl groups per monomer repeat unitwas prepared as described in Example VI except that the polymer had anumber average molecular weight of about 7,000 and a weight averagemolecular weight of about 25,000. A solution was prepared containingabout 2 parts by weight of the acryloylated polymer and about 3 parts byweight of N-methylpyrrolidinone. A chloromethylated polymer was preparedas described in Example IV having 2.0 chloromethyl groups per monomerrepeat unit with a number average molecular weight of about 5,000 and aweight average molecular weight of about 10,000. A solution was preparedcontaining about 2 parts by weight of the chloromethylated polymer andabout 3 parts by weight of N-methylpyrrolidinone. The two solutions weremixed together to form a solution containing about 40 percent weightsolids of a mixture containing 50 percent by weight of the acryloylatedpolymer and 50 percent by weight of the chloromethylated polymer. Asecond combined solution containing 40 weight percent solids wasprepared similarly except that the solids portion contained 75 percentby weight of the acryloylated polymer and 25 percent by weight of thechloromethylated polymer. A third combined solution containing 40 weightpercent solids was prepared similarly except that the solids portioncontained 90 percent by weight of the acryloylated polymer and 10percent by weight of the chloromethylated polymer. A first controlsolution was prepared containing 40 weight percent solids inN-methylpyrrolidone wherein the solids contained 100 percent by weightof the acryloylated polymer. A second control solution was prepared ofcomposition similar to the first control solution except that Michler'sketone was added to the solution in an amount of 3 percent by weight ofthe resin solids in the solution.

The five solutions were each spin coated onto glass slides (1 inch×1inch, that had previously been treated with 0.01 weight percent Z6020adhesion promoter in 95 parts methanol and 5 parts water (obtained fromDow Corning) and dried at 100° C. for 10 minutes) at 1,000 rpms for 30seconds. The films were soft baked in an oven for 10 minutes at 70° C.After cooling to 25° C., the films were covered width a mask and exposedto 365 nanometer UV light for various times amounting to between 100 and1,000 millijoules per square centimeter. The exposed films were thenpost exposure heated at 70° C. for 2 minutes, cooled to 25° C. over 5minutes, and then developed with a developer containing 60 percent byweight chloroform and 40 percent by weight cyclohexanone. The films werethen washed with a solution containing 90 percent by weight hexanes and10 percent by weight cyclohexanone, followed by drying at 70° C. for 2minutes. The cleanest features at the lowest energies were achieved withthe photoresist solutions in the following order, from best to worst:

1. 50 percent by weight acryloylated polymer, 50 percent by weightchloromethylated polymer;

2. 75 percent by weight acryloylated polymer, 25 percent by weightchloromethylated polymer;

3. control solution containing Michler's ketone;

4. 90 percent by weight acryloylated polymer, 10 percent by weightchloromethylated polymer;

5. 100 percent by weight acryloylated polymer (did riot polymerize underthe indicated conditions).

These results indicate that the chloromethylated polyarylene etherketone performs as an accelerator for the polymerization of acryloylgroups. While not being limited to any particular theory, it is believedthat one possible mechanism is the generation of free radicals on thechloromethylated polyarylene ether ketone which can add to the acryloylgroups on the acryloylated polyarylene ether ketone.

EXAMPLE X

A chloromethylated polyarylene ether ketone was prepared as described inExample V. A solution was then prepared containing 11 grams of thechloromethylated polymer in 100 milliliters (87.4 grams) ofN,N-dimethylacetamide and the solution was magnetically stirred at 25°C. with sodium acrylate (30 grams) for 1 week. The reaction mixture wasthen filtered and added to methanol using a Waring blender in relativeamounts of 25 milliliters of polymer solution per 0.75 liter ofmethanol. The white powder that precipitated was reprecipitated intomethanol from a 20 weight percent solids solution in methylene chlorideand was them air dried to yield 7.73 grams of a white powder. Thepolymer had 3 acrylate groups for every 4 repeating monomer units and 3chloromethyl groups for every 4 repeating monomer units. Thick films at30 microns were patterned at 600 dots per inch resolution, as previouslydescribed. The cured films were resistant to typical thermal ink jet inksolvents.

EXAMPLE XI

A polyarylene ether ketone having 3 acrylate groups for every 4repeating monomer units and 3 chloromethyl groups per repeating monomerunit and a weight average molecular weight of about 25,000 was preparedas described in Example VI. A photoresist solution was prepared bydissolving the chloromethyloted and acryloylmethylated polyarylene etherketone polymer in N-methylpyrrolidone at 20 percent by weight solids. To100 grams of this solution was added a second solution containing 2grams of EPON 1001 adhesive in 10 grams of N-methylpyrrolidone and athird solution containing 1 gram of “Y” curative (m-phenylenediamine)and 1 gram of Michler's ketone in 10 grams of N-methylpyrrolidone.

Phosphosilicate glass layers were spin coated with a solution of Z6020adhesion promoter (0.01 weight percent in 95 parts methanol and 5 partswater, Dow Corning) at 3000 revolutions per minute for 10 seconds anddried at 100° C. for between 2 and 10 minutes. The wafers were thenallowed to cool at 25° C. for 5 minutes before spin coating onto thewafers the photoresist solution prepared above at between 1,000 and3,000 revolutions per minute for between 30 and 60 seconds. The filmswere heated (soft baked) in an oven for between 10 and 15 minutes at 70°C. After cooling to 25° C. over 5 minutes, the films were covered withmasks and exposed to 365 nanometer ultraviolet light, amounting tobetween 150 and 1500 milliJoules per cm². The exposed wafers were thenheated at 70° C. for 2 minutes post exposure bake, followed by coolingto 25° C. over 5 minutes. The films were developed with 60:40chloroform/cyclohexanone developer, washed with 90:10hexanes/cyclohexanone, and then dried at 70° C. for 2 minutes. Half ofthe processed wafers were transferred to an oven at 25° C. containingordinary room air, and the other half of the processed wafers weretransferred to an oven at 25° C. containing an inert nitrogenatmosphere. The oven temperatures were raised from 25 to 120° C. at arate of 2° C. per minute; thereafter the wafers in the oven were soakedin an ink comprising 7.5 percent by weight BASF Basacid Black X-34 dye,10.5 percent by weight sulfolane, 15 percent by weight imidazole, 1percent by weight imidazole hydrochloride, and 66 percent by weightwater at 120° C. for 2 hours, followed by heating the wafers in the ovenfrom 120 to 260° C. at a rate of 2° C. per minute, soaking the wafers inink for 2 hours at 260° C., and cooling the wafers to 25° C. FourierTransform Infrared Spectroscopy indicated that the photoactivepolyarylene ether ketone underwent substantial oxidation during thethermal curing under ordinary room air. The oxidation mechanism wassubstantially reduced or eliminated when the polyarylene ether ketonewas cured under inert atmosphere. In addition, the adhesion of the inertatmosphere-cured polyarylene ether ketone to the heater wafer wassubstantially superior to that of the air-cured polyarylene ether ketoneto the heater wafer when soaked in ink at increased temperatures.Specifically, when soaked in an ink composition [comprising 10.0 percentby weight Projet Cyan 1 dye (10 percent by weight dye solids, obtainedfrom Zeneca), 25.0 percent by weight Basacid Black NBX-34 dye (30percent by weight dye solids, obtained from BASF), 21.0 percent byweight sulfolane (containing 95 percent by weight sulfolane, 5 percentby weight water, obtained from Phillips 66), 3.0 percent by weighttrimethylolpropane (obtained from Aldrich Chemical Co.), 2.0 percent byweight polyacrylic acid (MW 2,000, obtained from Aldrich Chemical Co.),1.0 percent by weight ammonium hydroxide (obtained from FisherScientific), 0.05 percent by weight polyethylene oxide (MW 18,500,obtained from Polysciences), and 37.95 percent by weight deionizedwater] at 60° C., the air cured films lifted from the heater waferwithin 10 days at peel strengths of 1,000 psi or less, whereas thenitrogen cured films withstood 21 days in the ink without noticeableeffect on the adhesion of the film to the heater wafer. Subsequent filmcoatings onto the inert atmosphere-cured layers also remained intact,indicating excellent adhesion to the nitrogen-cured polyarylene etherketone layer.

EXAMPLE XII

A chloromethylated polymer having 1.0 chloromethyl groups per repeatunit was prepared as described in Example IV. A 1-liter, 3-neck flaskequipped with a mechanical stirrer, argon inlet, and addition funnel wascharged with 175 milliliters of freshly distilled tetrahydrofuran.Sodium hydride (6 grams), obtained from Aldrich Chemical Co., Milwaukee,Wis., was added, followed by addition of 2-allyl phenol (5 grams)dropwise, resulting in vigorous hydrogen gas evolution. Thereafter, asolution containing 5 grams of the chloromethylated polyarylene etherketone in 50 milliliters of tetrahydrofuran was added. Stirring at 25°C. was continued for 48 hours. The resulting polymer was filtered andthe supernatant fluid was concentrated using a rotary evaporator. Theconcentrate was then added to methanol to precipitate the polymer,followed by in vacuo drying of the polymer.

The dried polymer (0.2 grams) in methylene chloride (100 milliliters)was then treated with 1 gram of m-chloroperoxybenzoic acid (obtainedfrom Aldrich Chemical Co., Milwaukee, Wis.) and magnetically stirred for2 hours in a 200 milliliter bottle. The polymer was then added tosaturated aqueous sodium bicarbonate (200 milliliters) and the methylenechloride was removed using a rotary evaporator. The resulting epoxidizedpolymer was filtered, washed with methanol (3 cups), and vacuum dried.

The epoxidized polymer in N-methyl pyrrolidinone (40 weight percentpolymer solids) was rendered photochemically active by the addition ofIrgacure 261 (obtained from Ciba-Geigy, Ardsley, N.Y.) to the solutionin an amount of 4 percent by weight of the polymer. Exposure toultraviolet light, followed by heating to 70° C., and development with acyclohexanone-methyl ethyl ketone mixture, yielded microlithographicpatterns. Subsequent thermal curing to 260° C. completely crosslinkedthe polymer, rendering it impervious to solvents such asN-methylpyrrolidinone, methylene chloride, acetone, and hexanes.

EXAMPLE XIII

The process of Example XII was repeated with the exception that 5 gramsof allyl alcohol were used instead of the 2-allylphenol. Similar resultswere obtained.

EXAMPLE XIV

A chloromethylated polymer having about 1.5 chloromethyl groups perrepeat unit was prepared as described in Example IV. Heater wafers withphosphosilicate glass layers were spin coated with a solution of Z6020adhesion promoter (0.01 weight percent in 95 parts methanol and 5 partswater, Dow Corning) at 3000 revolutions per minute for 10 seconds anddried at 100° C. for between 2 and 10 minutes. The wafers were thenallowed to cool at 25° C. for 5 minutes before spin coating thechloromethylated polyarylene ether ketone photoresist onto the wafer atbetween 1,000 and 3,000 revolutions per minute for between 30 and 60seconds. The photoresist solution was made by dissolving polyaryleneether ketone with 1 chloromethyl group per repeat unit and a weightaverage molecular weight of 11,000 in N-methylpyrrolidinone at 40 weightpercent solids. The films were heated (soft baked) in an oven at 80° C.for 15 minutes, followed by cooling to room temperature. Thereafter, thefilms were covered with masks and one set of coated glass slides wasexposed to the electron beam of a Hitachi scanning electron microscope(SEM) (Model S-2300) operated from about 8 to about 40 KV, with fromabout 12 to about 22 KV being preferred. A second set of coated glassslides was exposed to a 260 nanometer ultraviolet laser beam from aMolectron Corp. 10 Watt YAG laser with pulses up to 10 kiloHertz at 15nanoseconds or less per pulse and with up to 1 Joule per pulse.Subsequent to imagewise exposure, both sets of glass slides wereannealed in an oven at 80° C. for 2 minutes, followed by cooling to roomtemperature and development by washing with a mixture containing 60percent by volume cyclohexanone and 40 percent by volume chloroform. Thedeveloped slides were then washed with hexane and cured in an oven at250° C. for 2 hours to ensure complete polymerization of the resist. Thedeveloped resists exhibited very well defined features.

EXAMPLE XV

A polyarylene ether ketone of the formula

wherein n is between about 2 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 5-liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. Afterhours of heating 30 hours at 175° C. with continuous stirring, thereaction mixture was filtered to remove insoluble salts, and theresultant solution was added to methanol (5 gallons) to precipitate thepolymer. The polymer was isolated by filtration, and the wet filter cakewas washed with water (3 gallons) and then with methanol (3 gallons).The yield was 360 grams of vacuum dried polymer. The molecular weight ofthe polymer was determined by gel permeation chromatography (gpc)(elution solvent was tetrahydrofuran) with the following results: M_(n)2,800, M_(peak) 5,800, M_(w) 6,500, M_(z) 12,000 and M_(z+1) 17,700. Asa result of the stoichiometries used in the reaction, it is believedthat this polymer had end groups derived from bis-phenol A. When thereaction was allowed to proceed for 35, 40, and 48 hours at 175° C., therespective values of M_(n) of the poly(4-CPK-BPA) formed were 3,000,3,300, and 4,000.

A solution containing 100 parts by weight of the polyarylene etherketone thus prepared having a M_(n) of 2,800, 44.5 parts by weight ofparaformaldehyde, 1 part by weight sodium hydroxide, and 1 part byweight tetramethylammonium hydroxide in 200 parts by weight1,1,2,2-tetrachloroethane was heated at 100° C. Vigorous stirring andheating were continued for 16 hours. The resultant mixture was extractedwith water and the organic layer was dried over magnesium sulfate. Afterprecipitation into methanol, the filtered polymer was vacuum dried toyield 100 parts by weight hydroxymethylated polyarylene ether ketonewith 1.0 hydroxymethyl group per repeat unit.

Thereafter, 1 part by weight of the hydroxymethylated polymer thusformed was allowed to react with 1 part by weight of isocyanatoethylmethacrylate in 20 parts by weight methylene chloride to form anacryloylated and hydroxymethylated polymer at 25° C. within 16 hours.The resultant polymer had about 0.7 acryloyl groups per repeat unit.

EXAMPLE XVI

A hydroxymethylated polyarylene ether ketone was prepared as describedin Example XV. One part by weight of the hydroxymethylated polymer wasallowed to react with 1 part by weight of acryloyl chloride in 30 partsby weight methylene chloride in the presence of 1 part by weighttriethylamine. The reaction mixture was cooled in an ice bath, and theice bath was allowed to melt while the reaction mixture was stirred at25° C. for 16 hours. The resultant polymer had 0.6 acryloyl groups perrepeat unit.

EXAMPLE XVII

A chloromethylated polyarylene ether ketone having 1.5 chloromethylgroups per repeat unit is prepared as described in Example IV. Asolution containing 13.8 parts by weight of the chloromethylatedpolymer, 23 parts by weight tetrabutylammonium hydroxide, 7.6 partswater, and 50 parts by weight methylene chloride is stirred at 25° C.while 30 parts by weight of an aqueous sodium hydroxide solution (50percent by weight sodium hydroxide) is added. Stirring at 25° C. iscontinued for 16 hours, at which time the organic layer is separated,washed with water, dried over magnesium sulfate, and added to methanol(1 gallon) using a Waring blender to precipitate the polymer. Thefiltered polymer is vacuum dried to obtain about 12 parts by weight ofthe hydroxymethylated polymer containing 1 hydroxymethyl group perrepeat unit. Refluxing the reaction mixture results in nearly totalreplacement of the chloromethyl groups by the hydroxymethyl groups.

The hydroxymethylated polymer is then reacted with acryloyl chloride andisocyanatoethyl methacrylate as described in Example XV.

EXAMPLE XVIII

A polyarylene ether ketone of the formula

wherein n is between about 6 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 1 liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 53.90 grams), bis-phenol A (Aldrich 23,965-8, 45.42grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 1750C with continuous stirring, the reaction mixturewas tiltered to remove potassium carbonate and precipitated intomethanol (2 gallons). The polymer (poly(4-CPK-BPA)) was isolated in 86%yield after filtration and drying in vacuo. GPC analysis was as follows:M_(n) 4,239, M_(peak) 9,164, M_(w) 10,238, M_(z) 18,195, and M_(z+1)25,916. Solution cast films from methylene chloride were clear, tough,and flexible. As a result of the stoichiometries used in the reaction,it is believed that this polymer had end groups derived from4,4-dichlorobenzophenone.

EXAMPLE XIX

A benzophenone-terminated polyarylene ether ketone prepared as describedin Example XVIII was chloromethyl substituted as described in ExampleIV, resulting in a benzophenone-terminated, chloromethylated polymerhaving 0.5 chloromethyl groups per repeat unit.

A solution was prepared containing the benzophenone-terminatedchloromethylated polyarylene ether ketone thus prepared inN-methylpyrrolidinone at a concentration of 33.7 percent by weightpolymer solids. To this solution was added N,N-dimethyl ethylmethacrylate (obtained from Aldrich Chemical Co., Milwaukee, Wis.) in anamount of 6.21 percent by weight of the polymer solution, and theresulting solution was stirred for 2 hours. The reaction of thechloromethyl groups with the N,N-dimethyl ethyl methacrylate occurredquickly, resulting in formation of a polymer having about 0.5N,N-dimethyl ethyl methacrylate groups per monomer repeat unit.

The solution thus formed contained 40 percent by weight polymer solids.To this solution was added 1 part by weight Michier's ketone per 10parts by weight of the 40 percent by weight solids solution. Theresulting photoresist solution was coated onto spinning silane-treatedsilicon wafers and the coated wafers were heated at 70° C. for 10minutes. The wafers were then allowed to cool to 25° C., followed bycovering the wafers with masks and exposure to ultraviolet light at awavelength of 365 nanometers, amounting to 200 milliJoules/cm². Theexposed films were then heated to 70° C. for 5 minutes post exposurebake, followed by cooling to 25° C. The films were developed with 50:50methanol/water developer and then dried at 70° C. The processed waferswere transferred to an oven at 25° C., and the oven temperature wasraised at 2° C. per minute to 90° C., maintained at 90° C. for 2 hours,raised at 2° C. per minute to 260° C., maintained at 260° C. for 2hours, and then allowed to cool to 25° C. to effect post-cure. Duringpost-cure, heat stable, solvent resistant sites were formed. Thepost-cured, crosslinked polyarylene ether ketones were heat stable,chemically inert to thermal ink jet inks, electrically insulating, andmechanically robust, and exhibited low shrinkage during post-cure. Cleanfeatures were developed at resolutions of 300 and 600 dots per inch.

EXAMPLE XX

Fifty grams of a polymer having 0.75 acrylate groups per repeat unit and0.75 chloromethyl groups per repeat unit prepared as described inExample VI is dissolved in 117 milliliters of N,N-dimethylacetamide andmagnetically stirred at 5° C. in an ice bath with 30 milliliters oftrimethylamine. The reaction mixture is allowed to return to 25° C. overtwo hours and stirring is continued for an additional two hours. Theunreacted trimethylamine is then removed using a rotary evaporator andthe resulting polymer, which has both acrylate substituents andtrimethylammonium chloride substituents, is used as a photoresist asfollows.

A heater wafer with a phosphosilicate glass layer is spin coated with asolution of Z6020 adhesion promoter (0.01 weight percent in 95 partsmethanol and 5 parts water, Dow Corning) at 3000 revolutions per minutefor 10 seconds and dried at 100° C. for between 2 and 10 minutes. Thewafer is then allowed to cool at 25° C. for 5 minutes before spincoating the photoresist containing the photopatternable polymer onto thewafer at between 1,000 and 3,000 revolutions per minute for between 30and 60 seconds. The photoresist solution is made by combining the abovesolution at 30 weight percent solids with Michler's ketone (1.2 partsketone per every 40 parts of 40 weight percent solids polymer solution).The film is heated (soft baked) in an oven for between 10 and 15 minutesat 70° C. After cooling to 25° C. over 5 minutes, the film is coveredwith a mask and exposed to 365 nanometer ultraviolet light, amounting to200 millijoules per cm². The exposed wafer is then heated at 70° C. for2 minutes post exposure bake, followed by cooling to 25° C. over 5minutes. The film is developed with 50:50 water/methanol developer andthen dried at 70° C. for 2 minutes. A second developer/wash cycle iscarried out if necessary to obtain a wafer with clean features. Theprocessed wafer is transferred to an oven at 25° C., and the oventemperature is raised from 25 to 90° C. at 2° C. per minute. Thetemperature is maintained at 90° C. for 2 hours, and then increased to260° C. at 2° C. per minute. The oven temperature is maintained at 260°C. for 2 hours and then the oven is turned off and the temperature isallowed to cool gradually to 25° C. When thermal cure of the photoresistfilms is carried out under inert atmosphere, such as nitrogen or one ofthe noble gases, such as argon, neon, krypton, xenon, or the like, thereis markedly reduced oxidation of the developed film and improved thermaland hydrolytic stability of the resultant devices. Moreover, adhesion ofdeveloped photoresist film is improved to the underlying substrate. If asecond layer is spin coated over the first layer, the heat cure of thefirst developed layer can be stopped between 80 and 260° C. before thesecond layer is spin coated onto the first layer. A second thicker layeris deposited by repeating the above procedure a second time. It isbelieved that films at 15 microns con be developed with clean featuresat 600 dots per inch.

EXAMPLE XXI

A first acryloylated polyarylene ether ketone resin having 1 acrylategroup per repeating monomer unit and one chloromethyl group perrepeating monomer unit and having a weight average molecular weight ofabout 60,000 was prepared as follows. A 1 liter, 3-neck round-bottomflask equipped with a Dean-Stork (Barrett) tap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 50 grams), bis-phenol A (Aldrich 23,965-8, 48.96grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 48hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove potassium carbonate and precipitated intomethanol (2 gallons). The polymer (poly(4-CPK-BPA)) was isolated afterfiltration and drying in vacuo. Gel permeation chromatography (gpc)(elution solvent was tetrahydrofuran) analysis was as follows: M_(n)3,360, M_(peak) 9,139, M_(w) 5,875, M_(z) 19,328, and M_(z+1) 29,739.Solution cast films from methylene chloride were clear, tough, andflexible. As a result of the stoichiometries used in the reaction, it isbelieved that this polymer had end groups derived from bis-phenol A. Thepolymer thus prepared was chloromethyloted as follows. A solution ofchloromethyl ether in methyl acetate was made by adding 282.68 grams(256 milliliters) of acetyl chloride to a mixture of dimethoxy methane(313.6 grams, 366.8 milliliters) and methanol (10 milliliters) in a 5liter 3-neck round-bottom flask equipped with a mechanical stirrer,argon inlet, reflux condenser, and addition funnel. The solution wasdiluted with 1,066.8 milliliters of 1,1,2,2-tetrachloroethane and thentin tetrachloride (2.4 milliliters) was added via a gas-tight syringealong with 1,1,2,2-tetrachloroethane (133.2 milliliters) using anaddition funnel. The reaction solution was heated to 500° C. Thereafter,a solution of the poly(4-CPK-BPA) (160.8 grams) in 1,000 milliliters oftetrochloroethane was added rapidly. The reaction mixture was thenheated to reflux with an oil bath set at 110° C. After 4 hours refluxwith continuous stirring, heating was discontinued and the mixture wasallowed to cool to 25° C. The reaction mixture was transferred in stagesto a 2 liter round bottom flask and concentrated using a rotaryevaporator with gentle heating up to 50° C. while reduced pressure wasmaintained with a vacuum pump trapped with liquid nitrogen. Theconcentrate was added to methanol (4 gallons) to precipitate the polymerusing a Waring blender. The polymer was isolated by filtration andvacuum dried to yield poly(4-CPK-BPA) with 2 chloromethyl groups perrepeat unit as identified using ¹H NMR spectroscopy. Solvent freepolymer was obtained by reprecipitation of the polymer (75 grams) inmethylene chloride (500 grams) into methanol (3 gallons) followed byfiltration and vacuum drying to yield solvent free polymer. Gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)analysis was as follows: M_(n) 4,527, M_(peak) 12,964, M_(w) 12,179,M_(z) 21,824, and M_(z+1) 30,612. The chloromethylated polymer was thenacryloylated as follows. A solution was prepared containing 90 grams ofthe chloromethylated polymer with 2 chloromethyl groups per repeat unitin 639 milliliters (558.5 grams) of N,N-dimethylacetamide and thesolution was magnetically stirred at 25° C. with sodium acrylate (51.39grams) for 1 week. The reaction mixture was then centrifuged, and thesupernate was added to methanol (4.8 gallons) using a Waring blender inrelative amounts of 25 milliliters of polymer solution per 0.75 liter ofmethanol. The white powder that precipitated was filtered, and the wetfilter cake was washed with water (3 gallons) and then methanol (3gallons). The polymer was then isolated by filtration and vacuum driedto yield a white powder. The polymer had 1 acrylate group for everyrepeating monomer unit and 1 chloromethyl groups for every repeatingmonomer unit. Gel permeation chromatography (gpc) (elution solvent wastetrahydrofuran) analysis was as follows: M_(n) 10,922, M_(peak) 24,895,M_(w) 62,933, M_(z) 210,546, and M_(z+1) 411,394.

A second acryloylated polyarylene ether ketone resin with a weightaverage molecular weight of about 8,000 and having 1 acrylate group perevery eight repeating monomer units and 1 chloromethyl group per everyeight repeating monomer units was prepared as follows. A 1 liter, 3-neckround-bottom flask equipped with a Dean-Stark (Barrett) trap, condenser,mechanical stirrer, argon inlet, and stopper was situated in a siliconeoil bath. 4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich ChemicalCo., Milwaukee, Wis., 50 grams), bis-phenol A (Aldrich 23,965-8, 48.96grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 175° C. with continuous stirring, an aliquot of thereaction product that had been precipitated into methanol was analyzedby gel permeation chromatography (gpc) (elution solvent wastetrahydrofuran) with the following results: M_(n) 4464, M_(peak) 7583,M_(w) 7927, M_(z) 12,331, and M_(z+1) 16,980. As a result of thestoichiometries used in the reaction, it is believed that this polymerhad end groups derived from bis-phenol A. This polymer contained 7 mol %N,N-dimethylacetamide as residual solvent. When the residualN,N-dimethylacetamide exceeds 5 mol %, of the polymer, thechloromethylation reaction of the next step proceeds only to a maximumvalue of 1 chloromethyl group per every 4 monomer repeat units. Asolution of chloromethyl ether in methyl acetate was made by adding 35.3grams of acetyl chloride to a mixture of dimethoxy methane (45milliliters) and methanol (1.25 milliliters) in a 500 milliliter 3-neckround-bottom flask equipped with a mechanical stirrer, argon inlet,reflux condenser, and addition funnel. The solution was diluted with 150milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3milliliters) was added via syringe. The solution was heated to refluxwith an oil bath set at 110° C. Thereafter, a solution of thepoly(4-CPK-BPA) containing residual solvent (10 grams of polymer) in 125milliliters of 1,1,2,2-tetrachloroethane was added over 8 minutes. Aftertwo hours reflux with continuous stirring, heating was discontinued andthe mixture was allowed to cool to 25° C. The reaction mixture wastransferred to a rotary evaporator with gentle heating at between 50 and55° C. After 1 hour, when most of the volatiles had been removed, thereaction mixture was added to methanol (each 25 milliliters of solutionwas added to 0.75 liter of methanol) to precipitate the polymer using aWaring blender. The precipitated polymer was collected by filtration,washed with methanol, and air-dried to yield 13 grams of off-whitepowder. The polymer had about 1.0 CH₂Cl groups per every 4 repeat units.A solution was then prepared containing 11 grams of the chloromethylatedpolymer in 100 milliliters (87.4 grams) of N,N-dimethylacetamide and thesolution was magnetically stirred at 25° C. with sodium acrylate (30grams) for 1 week. The reaction mixture was then filtered and added tomethanol using a Waring blender in relative amounts of 25 milliliters ofpolymer solution per 0.75 liter of methanol. The white powder thatprecipitated was reprecipitated into methanol from a 20 weight percentsolids solution in methylene chloride and was them air dried to yield7.73 grams of a white powder. The polymer had 1 acrylate group for every8 repeat units, and 1 chloromethyl group for every 8 repeat units.

50 parts by weight of the first polymer were admixed with 50 parts byweight of the second polymer to result in a mixture containing equalparts by weight of both polymers. A solution was prepared containing 40percent by weight solids of the polymer mixture in N-methylpyrrolidone.Thereafter, a sensitizer (Michier's ketone) was added to the solution inan amount of about 0.75 percent by weight of the solution and moresolvent was added, bringing the solution to a solids content of 37percent by weight. The resulting blend had a weight average molecularweight of about 34,000 and a degree of acryloylation of about 0.78milliequivalents of acryloyl groups per gram of resin.

The solution thus formed was coated onto spinning silane-treated siliconwafers and the coated wafers were heated at 70° C. for 5 minutes. Thewafers were then allowed to cool to 25° C., followed by covering thewafers with masks and exposure to ultraviolet light al a wavelength of365 nanometers, amounting to 2,500 milliJoules/cm². The exposed filmswere then heated to 70° C. for 5 minutes post exposure bake, followed bycooling to 25° C. The films were developed with 60:40chloroform/cyclohexanone developer, washed with 90:10hexanes/cyclohexanone, and then dried at 70° C. The processed waferswere transferred to an oven at 25° C., and the oven temperature wasraised at 2° C. per minute to 260° C. to effect post-cure. Duringpost-cure, heat stable, solvent resistant sites were formed. Thepost-cured, crosslinked polymers were heat stable, chemically inert tothermal ink jet inks (including a black ink available from Canon K.K.with a pH of 9.6 after exposure to the ink for 5 weeks at 65° C.),electrically insulating, and mechanically robust, and exhibited lowshrinkage during post-cure. Clean features were developed at resolutionsof 300 and 600 dots per inch.

EXAMPLE XXII

An acryloylated poly(4-CPK-BPA) with a weight average molecular weightof about 60,000 and having 1 acryloyl group per repeat unit and 1chloromethyl group per repeat unit (7 grams), prepared as described inExample XXI, of the structure

and a poly(4-CPK-BPA) with a weight average molecular weight of 5,600 (3grams), prepared in a manner similar to that described for thepreparation of poly(4-CPK-BPA) of M_(w) 5,875 in Example I except thatheating at 175° C. was for 30 hours instead of 48 hours, of thestructure

were combined and diluted to 37 weight percent solids withN-methylpyrrolidinone (15 grams). Michler's ketone of the formula

was added in an amount of from about 0.3 to about 0.5 percent by weightof the resin solids before exposure to develop 30 micron thick films.The resulting blend had a weight average molecular weight of about44,000 and a degree of acryloylation of about 1.31 milliequivalents ofacryloyl groups per gram of resin. A heater wafer with a phosphosilicateglass layer was spin coated with a solution of Z6020 adhesion promoter(0.01 weight percent in methanol {95 parts} and water {5 parts},available from Dow Corning) at 3000 revolutions per minute for 10seconds and dried at 100° C. for between 2 and 10 minutes. The wafer wasthen allowed to cool at 25° C. over 5 minutes before spin coating thepolyarylene ether ketone blended photoresist solution onto the wafer atbetween 1000 and 3000 revolutions per minute for between 30 and 60seconds. The film was heated (soft baked) in an oven for between 10 and15 minutes at 70° C. After cooling to 25° C. over 5 minutes, the filmwas covered with a mask and exposed to 365 nanometer ultraviolet light,amounting to between 150 and 1500 milliJoules per cm². The exposed waferwas then heated at 70° C. for 2 minutes post exposure bake, followed bycooling to 25° C. over 5 minutes. The film was developed with 6:4chloroform/cyclohexanone developer, washed with 9:1hexanes/cyclohexanone and then dried at 70° C. for 2 minutes. A seconddeveloper/wash cycle was carried out if necessary to obtain a wafer withclean features. The processed wafer was transferred to an oven at 25°C., and the oven temperature was raised from 25 to 90° C. at 2° C. perminute. The temperature was maintained at 90° C. for 2 hours, and thenincreased to 260° C. at 2° C. per minute. The oven temperature wasmaintained at 260° C. for 2 hours and then the oven was turned off andthe temperature was allowed to gradually cool to 25° C. When thermalcure of the photoresist films was carried out under inert atmospheresuch as argon or nitrogen, there was markedly reduced oxidation of thedeveloped film and improved thermal and hydrolytic stability of theresultant devices. Moreover, adhesion was improved to the underlyingsubstrate. If desired, the heat cure of the first developed layer can bestopped between 80 and 260° C. before the second layer is spin coated ontop. A second thicker layer was deposited by repeating the aboveprocedure a second time. This process is intended to be a guide in thatprocedures can be outside the specified conditions depending on filmthickness and photoresist molecular weight. Films at 30 microns weredeveloped with clean features at 600 dots per inch. The photopatternablepolymer blend solution was further admixed with epoxy resin in relativeamounts of about 90 parts by weight polymer and about 10 parts by weightepoxy resin, EPON 1001F, available from Shell Chemical Company, Houston,Tex., believed to be of the formula

“Y” curative (meta-phenylene diamine) was used to cure the epoxy resinat 10 weight percent addition of curative per gram of epoxy resinsolids. The same spin conditions, soft bake, photoexposure, anddevelopment conditions were used in the case of the epoxy blend as inthat without the epoxy resin material. Incorporation of the epoxy resininto the photopatternable polymer material improved the adhesion of thephotopatternable layer to the heater plate. Subsequent to imaging andduring cure of the photopatternable polymer, the epoxy reacted with theheater layer to form strong chemical bonds with that layer, improvingadhesive strength and solvent resistance of the interface. The presenceof the epoxy may also improve the hydrophilicity of the photopatternablepolymer and thus may improve the wetting properties of the layer,thereby improving the refill characteristics of the printhead. Thermalink jet printhead devices were made with the above composition whichresisted sulfolane based ink jet compositions and alkaline inks of pH 8which contained N-cyclohexylpyrrolidinone and imidazole.

EXAMPLE XXIII

An acryloylated poly(4-CPK-BPA) with a weight average molecular weightof about 25,000 and having 0.75 acryloyl group and 0.75 chloromethylgroup per repeat unit of the structure

was prepared as follows. A 1 liter, 3-neck round-bottom flask equippedwith a Dean-Stark (Barrett) trap, condenser, mechanical stirrer, argoninlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 53.90 grams), bis-phenol A (Aldrich 23,965-8, 45.42grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove potassium carbonate and precipitated intomethanol (2 gallons). The polymer (poly(4-CPK-BPA)) was isolated in 86%yield after filtration and drying in vacuo. As a result of thestoichiometries used in the reaction, it is believed that this polymerhad end groups derived from 4,4-dichlorobenzophenone. Gel permeationchromatography (gpc) (elution solvent was tetrahydrofuran) analysis wasas follows: M_(n) 4,334, M_(peak) 10,214, M_(w) 11,068, M_(z) 10,214,and M_(z+1) 28,915. Solution cast films from methylene chloride wereclear, tough, and flexible. The polymer thus prepared waschloromethylated as follows. A solution of chloromethyl ether in methylacetate was made by adding 282.68 grams (256 milliliters) of acetylchloride to a mixture of dimethoxy methane (313.6 grams, 366.8milliliters) and methanol (10 milliliters) in a 5 liter 3-neckround-bottom flask equipped with a mechanical stirrer, argon inlet,reflux condenser, and addition funnel. The solution was diluted with1,066.8 milliliters of 1,1,2,2-tetrachloroethane and then tintetrachloride (2.4 milliliters) was added via a gas-tight syringe alongwith 1,1,2,2-tetrachloroethane (133.2 milliliters) using an additionfunnel. The reaction solution was heated to 500° C. Thereafter, asolution of the poly(4-CPK-BPA) (160.8 grams) in 1,000 milliliters oftetrachloroethane was added rapidly. The reaction mixture was thenheated to reflux with an oil bath set at 110° C. After 4 hours refluxwith continuous stirring, heating was discontinued and the mixture wasallowed to cool to 25° C. The reaction mixture was transferred in stagesto a 2 liter round bottom flask and concentrated using a rotaryevaporator with gentle heating up to 50° C. while reduced pressure wasmaintained with a vacuum pump trapped with liquid nitrogen. Theconcentrate was added to methanol (4 gallons) to precipitate the polymerusing a Waring blender. The polymer was isolated by filtration andvacuum dried to yield 200 grams of poly(4-CPK-BPA) with 1.5 chloromethylgroups per repeat unit as identified using ¹H NMR spectroscopy. Solventfree polymer was obtained by reprecipitation of the polymer (75 grams)in methylene chloride (500 grams) into methanol (3 gallons) followed byfiltration and vacuum drying. Gel permeation chromatography (gpc)(elution solvent was tetrahydrofuran) analysis was as follows: M_(n)5,580, M_(peak) 15,242, M_(w) 17,169, M_(z) 36,837, and M_(z+1) 57,851.The chloromethylated polymer was then acryloylated as follows. Asolution was prepared containing 90 grams of the chloromethylatedpolymer with 2 chloromethyl groups per repeat unit in 639 milliliters(558.5 grams) of N,N-dimethylacetamide and the solution was magneticallystirred at 25° C. with sodium acrylate (51.39 grams) for 1 week. Thereaction mixture was then centrifuged, and the supernate was added tomethanol (4.8 gallons) using a Waring blender in relative amounts of 25milliliters of polymer solution per 0.75 liter of methanol. The whitepowder that precipitated was filtered, and the wet filter cake waswashed with water (3 gallons) and then methanol (3 gallons). The polymerwas then isolated by filtration and vacuum dried to yield a whitepowder. The polymer had 0.75 acrylate group for every repeating monomerunit and 0.75 chloromethyl group for every repeating monomer unit. Gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)analysis was as follows: M_(n) 7,000, M_(peak) 17,376, M_(w) 22,295,M_(z) 50,303, and M_(z+1) 80,995.

A poly(4-CPK-BPA) with a weight average molecular weight of 11,000 andhaving 2 chloromethyl groups per repeat unit, of the structure

was prepared as described in Example XXI. Thereafter, 7 grams of theacryloylated and chloromethylated polymer with weight average molecularweight of about 25,000 and 3 grams of the chloromethylated polymer withweight average molecular weight of about 11,000 were combined anddiluted to 37 weight percent solids with N-methylpyrrolidinone (15grams). Michier's ketone of the formula

was added in an amount of from about 0.3 to about 0.5 percent by weightof the resin solids before exposure to develop 30 micron thick films.The blend had a weight average molecular weight of about 20,800 and adegree of acryloylation of about 1.05 milliequivalents per gram. Aheater wafer with a phosphosilicate glass layer was spin coated with asolution of Z6020 adhesion promoter (0.01 weight percent in methanol {95parts} and water {5 parts}, available from Dow Corning) at 3000revolutions per minute for 10 seconds and dried at 100° C. for between 2and 10 minutes. The wafer was then allowed to cool at 25° C. over 5minutes before spin coating the polyarylene ether ketone blendedphotoresist solution onto the wafer at between 1000 and 3000 revolutionsper minute for between 30 and 60 seconds. The film was heated (softbaked) in an oven for between 10 and 15 minutes at 70° C. After coolingto 25° C. over 5 minutes, the film was covered with a mask and exposedto 365 nanometer ultraviolet light, amounting to between 150 and 1500milliJoules per cm². The exposed wafer was then heated at 70° C. for 2minutes post exposure bake, followed by cooling to 25° C. over 5minutes. The film was developed with 6:4 chloroform/cyclohexanonedeveloper, washed with 9:1 hexanes/cyclohexanone and then dried at 70°C. for 2 minutes. A second developer/wash cycle was carried out ifnecessary to obtain a wafer with clean features. The processed wafer wastransferred to an oven at 25° C., and the oven temperature was raisedfrom 25 to 90° C. at 2° C. per minute. The temperature was maintained at90° C. for 2 hours, and then increased to 260° C. at 2° C. per minute.The oven temperature was maintained at 260° C. for 2 hours and then theoven was turned off and the temperature was allowed to gradually cool to25° C. When thermal cure of the photoresist films was carried out underinert atmosphere such as argon or nitrogen, there was markedly reducedoxidation of the developed film and improved thermal and hydrolyticstability of the resultant devices. Moreover, adhesion was improved tothe underlying substrate. If desired, the heat cure of the firstdeveloped layer can be stopped between 80 and 260° C. before the secondlayer is spin coated on top. A second thicker layer was deposited byrepeating the above procedure a second time. This process is intended tobe a guide in that procedures can be outside the specified conditionsdepending on film thickness and photoresist molecular weight. Films at30 microns were developed with clean features at 600 dots per inch. Thephotopatternable polymer blend solution was further admixed with epoxyresin in relative amounts of about 90 parts by weight polymer and about10 parts by weight epoxy resin, EPON 1001F, available from ShellChemical Company, Houston, Tex., believed to be of the formula

“Y” curative (meta-phenylene diamine) was used to cure the epoxy resinat 10 weight percent addition of curative per gram of epoxy resinsolids. The same spin conditions, soft bake, photoexposure, anddevelopment conditions were used in the case of the epoxy blend as inthat without the epoxy resin material. Incorporation of the epoxy resininto the photopatternable polymer material improved the adhesion of thephotopatternable layer to the heater plate. Subsequent to imaging andduring cure of the photopatternable polymer, the epoxy reacted with theheater layer to form strong chemical bonds with that layer, improvingadhesive strength and solvent resistance of the interface. The presenceof the epoxy may also improve the hydrophilicity of the photopatternablepolymer and thus may improve the wetting properties of the layer,thereby improving the refill characteristics of the printhead. Thermalink jet printhead devices were made with the above composition whichresisted sulfolane based ink jet compositions and alkaline inks of pH 8which contained N-cyclohexylpyrrolidinone and imidazole.

EXAMPLE XXIV

Acryloylated poly(4-CPK-BPA) with a weight average molecular weight of60,000 and having 0.75 acryloyl group and 0.75 chloromethyl group perrepeat unit, of the general structure

is prepared as follows. A 1 liter, 3-neck round-bottom flask equippedwith a Dean-Stark (Barrett) trap, condenser, mechanical stirrer, argoninlet, and stopper is situated in a silicone oil bath.4,4′-Dichiorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 50 grams), bis-phenol A (Aldrich 23,965-8, 48.96grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)are added to the flask arid heated to 175° C. (oil bath temperature)while the volatile toluene component is collected and removed. After 24hours of heating at 175° C. with continuous stirring, it is believedthat the reaction product precipitated into methanol, if analyzed by gelpermeation chromatography (gpc) (elution solvent is tetrahydrofuran),will have approximately the following results: M_(n) 3100, M_(w) 6250.As a result of the stoichiometries used in the reaction, it is believedthat this polymer will have end groups derived from bis-phenol A. Thispolymer contains 7 mol % N,N-dimethylacetamide as residual solvent. Whenthe residual N,N-dimethylacetamide exceeds 5 mol % of the polymer, thechloromethylation reaction of the next step proceeds only to a maximumvalue of 1 chloromethyl group per every 4 monomer repeat units. Asolution of chloromethyl ether in methyl acetate is made by adding 35.3grams of acetyl chloride to a mixture of dimethoxy methane (45milliliters) and methanol (1.25 milliliters) in a 500 milliliter 3-neckround-bottom flask equipped with a mechanical stirrer, argon inlet,reflux condenser, and addition funnel. The solution is diluted with 150milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3milliliters) is added via syringe. The solution is heated to reflux withan oil bath set at 110° C. Thereafter, a solution of the poly(4-CPK-BPA)containing residual solvent (10 grams of polymer) in 125 milliliters of1,1,2,2-tetrachloroethane is added over 8 minutes. After two hoursreflux with continuous stirring, heating is discontinued and the mixtureis allowed to cool to 25° C. The reaction mixture is transferred to arotary evaporator with gentle heating at between 50 and 55° C. After 1hour, when most of the volatiles have been removed, the reaction mixtureis added to methanol (each 25 milliliters of solution is added to 0.75liter of methanol) to precipitate the polymer using a Waring blender.The precipitated polymer is collected by filtration, washed withmethanol, and air-dried to yield off-white powder. It is believed thatthe polymer will have about 1 CH₂Cl group per every 4 repeat units. Asolution is then prepared containing 11 grams of the chloromethylatedpolymer in 100 milliliters (87.4 grams) of N,N-dimethylacetamide and thesolution is magnetically stirred at 25° C. with sodium acrylate (30grams) for 1 week. The reaction mixture is then filtered and added tomethanol using a Waring blender in relative amounts of 25 milliliters ofpolymer solution per 0.75 liter of methanol. The white powder thatprecipitates is reprecipitated into methanol from a 20 weight percentsolids solution in methylene chloride and is then air dried to yield awhite powder. It is believed that the polymer will have 1 acrylate groupfor every 8 repeat units, and 1 chloromethyl group for every 8 repeatunits.

Bisphenol A bispropylene glycol dimethacrylate, molecular weight 512, isprepared as disclosed in, for example, “Bis-Methacryloxy Bisphenol-AEpoxy Networks: Synthesis, Characterization, Thermal and MechanicalProperties,” A. Banthia et al., Polymer Preprints, 22(1), 209 (1981),the disclosure of which is totally incorporated herein by reference, ofthe structure

The acryloylated and chloromethylated polymer (8 grams) and thebisphenol A bispropylene glycol dimethacrylate are combined and dilutedto 37 weight percent solids with N-methylpyrrolidinone (15 grams). Theresulting blend has a weight average molecular weight of about 20,000and a degree of acryloylation of about 1.27 milliequivalents of acryloylgroups per gram of blend. Michler's ketone is added in an amount of fromabout 0.3 to about 0.5 percent by weight of the resin solids beforeexposure to develop 30 micron thick films. A heater wafer with aphosphosilicate glass layer is spin coaled with a solution of Z6020adhesion promoter (0.01 weight percent in methanol {95 parts} and water{5 parts}, available from Dow Corning) at 3000 revolutions per minutefor 10 seconds and dried at 100° C. for between 2 and 10 minutes. Thewafer is then allowed to cool at 25° C. over 5 minutes before spincoating the polyarylene ether ketone blended photoresist solution ontothe wafer at between 1000 and 3000 revolutions per minute for between 30and 60 seconds. The film is heated (soft baked) in an oven for between10 and 15 minutes at 70° C. After cooling to 25° C. over 5 minutes, thefilm is covered with a mask and exposed to 365 nanometer ultravioletlight, amounting to between 150 and 1500 milliJoules per cm². Theexposed wafer is then heated at 70° C. for 2 minutes post exposure bake,followed by cooling to 25° C. over 5 minutes. The film is developed with6:4 chloroform/cyclohexanone developer, washed with 9:1hexanes/cyclohexanone and then dried at 70° C. for 2 minutes. A seconddeveloper/wash cycle is carried out if necessary to obtain a wafer withclean features. The processed wafer is transferred to an oven at 25° C.,and the oven temperature is raised from 25 to 90° C. at 2° C. perminute. The temperature is maintained at 90° C. for 2 hours, and thenincreased to 260° C. at 2° C. per minute. The oven temperature ismaintained at 260° C. for 2 hours and then the oven is turned off andthe temperature is allowed to cool gradually to 25° C. When thermal cureof the photoresist films is carried out under inert atmosphere such asargon or nitrogen, there is markedly reduced oxidation of the developedfilm and improved thermal and hydrolytic stability of the resultantdevices. Moreover, adhesion is improved to the underlying substrate. Ifdesired, the heat cure of the first developed layer can be stoppedbetween 80 and 260° C. before the second layer is spin coated on top. Asecond thicker layer is deposited by repeating the above procedure asecond time. This process is intended to be a guide in that procedurescan be outside the specified conditions depending on film thickness andphotoresist molecular weight. Films at 30 microns can be developed withclean features at 600 dots per inch.

EXAMPLE XXV

Acryloylated poly(4-CPK-BPA) with a weight average molecular weight of25,000 and having 0.75 acryloyl group and 0.75 chloromethyl group perrepeat unit (80 parts by weight), of the structure

prepared as described in Example XXIII, and polymethyl methacrylatehaving a weight average molecular weight of 15,000 (obtained from SigmaChemical Co., St. Louis, Mo.) (20 parts by weight) are combined anddiluted to 37 weight percent solids with N-methylpyrrolidinone (150grams). The resulting blend had a weight average molecular weight ofabout 23,000 and a degree of acryloylation of 1.20 milliequivalents pergram. Michler's ketone is added in an amount of about 1.5 percent byweight of the resin solids before exposure to develop 30 micron thickfilms. A heater wafer with a phosphosilicate glass layer is spin coatedwith a solution of Z6020 adhesion promoter (0.01 weight percent inmethanol {95 parts} and water {5 parts}, available from Dow Corning) at3000 revolutions per minute for 10 seconds and dried at 100° C. forbetween 2 and 10 minutes. The wafer is then allowed to cool at 25° C.over 5 minutes before spin coating the polyarylene ether ketone blendedphotoresist solution onto the wafer at between 1000 and 3000 revolutionsper minute for between 30 and 60 seconds. The film is heated (softbaked) in an oven for between 10 and 15 minutes at 70° C. After coolingto 25° C. over 5 minutes, the film is covered with a mask and exposed to365 nanometer ultraviolet light, amounting to between 150 and 1500milliJoules per cm². The exposed wafer is then heated at 70° C. for 2minutes post exposure bake, followed by cooling to 25° C. over 5minutes. The film is developed with 6:4 chloroform/cyclohexanonedeveloper, washed with 9:1 hexanes/cyclohexanone and then dried at 70°C. for 2 minutes. A second developer/wash cycle is carried out ifnecessary to obtain a wafer with clean features. The processed wafer istransferred to an oven at 25° C., and the oven temperature is raisedfrom 25 to 90° C. at 2° C. per minute. The temperature is maintained at90° C. for 2 hours, and then increased to 260° C. at 2° C. per minute.The oven temperature is maintained at 260° C. for 2 hours and then theoven is turned off and the temperature is allowed to cool gradually to25° C. When thermal cure of the photoresist films is carried out underinert atmosphere such as argon or nitrogen, it is believed that therewill be markedly reduced oxidation of the developed film and improvedthermal and hydrolytic stability of the resultant devices. Moreover, itis believed that adhesion will be improved to the underlying substrate,If desired, the heat cure of the first developed layer can be stoppedbetween 80 and 260° C. before the second layer is spin coated on top. Asecond thicker layer is deposited by repeating the above procedure asecond time. This process is intended to be a guide in that procedurescan be outside the specified conditions depending on film thickness andphotoresist molecular weight. It is believed that films at 30 micronscan be developed with clean features at 600 dots per inch.

EXAMPLE XXVI

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 500 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), bis(4-hydroxyphenyl)methane(Aldrich, 14.02 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-BPM), was 24 grams. The polymer dissolved on heating inN-methylpyrrolidinone, N,N-dimethylacetamide, and1,1,2,2-tetrachloroethane. The polymer remained soluble after thesolution had cooled to 25° C.

EXAMPLE XXVII

The polymer poly(4-CPK-BPM), prepared as described in Example XXVI, wasacryloylated with paraformaldehyde by the process described in ExampleII. Similar results were obtained.

EXAMPLE XXVIII

The polymer poly(4-CPK-BPM), prepared as described in Example XXVI, waschloromethylated as follows. A solution of chloromethyl methyl ether (6mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (35.3 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 150milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3milliliters) was added. After taking the mixture to reflux using an oilbath set at 110° C., a solution of poly(4-CPK-BPM) (10 grams) in 125milliliters of 1,1,2,2-tetrachloroethane was added. Reflux wasmaintained for 2 hours and then 5 milliliters of methanol were added toquench the reaction. The reaction solution was added to 1 gallon ofmethanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-BPM), which was collected by filtration andvacuum dried. The yield was 9.46 grams of poly(4-CPK-BPM) with 2chloromethyl groups per polymer repeat unit. The polymer had thefollowing structure:

EXAMPLE XXIX

Poly(4-CPK-BPM) with 2 chloromethyl groups per repeat unit (1 gram,prepared as described in Example XXVIII) in 20 milliliters ofN,N-dimethylacetamide was magnetically stirred with sodium acrylate for112 hours at 25° C. The solution was added to methanol using a Waringblender to precipitate the polymer, which was filtered and vacuum dried.Between 58 and 69 percent of the chloromethyl groups had been replacedwith acryloyl groups. The product had the following formula:

EXAMPLE XXX

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 500 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), hexafluorobisphenol A(Aldrich, 23.52 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-HFBPA), was 20 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,975, M_(peak) 2,281, M_(w) 3,588,and M_(z+1) 8,918.

EXAMPLE XXXI

The polymer poly(4-CPK-HFBPA), prepared as described in Example XXX, wasacryloylated with paraformaldehyde by the process described in ExampleII. Similar results were obtained.

EXAMPLE XXXII

The polymer poly(4-CPK-HFBPA), prepared as described in Example XXX, ischloromethylated by the process described in Example XXVIII. It isbelieved that similar results will be obtained.

EXAMPLE XXXII

The chloromethylated polymer poly(4-CPK-HFE;PA), prepared as describedin Example XXXII, is acryloylated by the process described in ExampleXXIX. It is believed that similar results will be obtained.

EXAMPLE XXXIV

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 43.47grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.06 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 5 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The solidified masswas treated with acetic acid (vinegar) and extracted with methylenechloride, filtered, and added to methanol to precipitate the polymer,which was collected by filtration, washed with water, and then washedwith methanol. The yield of vacuum dried product, poly(4-FPK-FBPA), was71.7 grams. The polymer was analyzed by gel permeation chromatography(gpc) (elution solvent was tetrahydrofuran) with the following results:M_(n) 59,100, M_(peak) 144,000, M_(w) 136,100, M_(z) 211,350, andM_(z+1) 286,100.

EXAMPLE XXXV

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 50.02grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.04 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The reaction mixturewas filtered and added to methanol to precipitate the polymer, which wascollected by filtration, washed with water, and then washed withmethanol. The yield of vacuum dried product, poly(4-CPK-FBP), was 60grams.

EXAMPLE XXXVI

The polymer poly(4-CPK-FBP), prepared as described in Example XXXV, waschloromethylated as follows. A solution of chloromethyl methyl ether (6mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (38.8 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 100milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.5milliliters) was added in 50 milliliters of 1,1,2,2-tetrachloroethane.After taking the mixture to reflux using an oil bath set at 100° C., asolution of poly(4-CPK-FBP) (10 grams) in 125 milliliters of1,1,2,2-tetrachloroethane was added. The reaction temperature wasmaintained at 100° C. for 1 hour and then 5 milliliters of methanol wereadded to quench the reaction. The reaction solution was added to 1gallon of methanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-FBP), which was collected by filtration andvacuum dried. The yield was 9.5 grams of poly(4-CPK-FBP) with 1.5chloromethyl groups per polymer repeat unit. When the reaction wascarried out at 110° C. (oil bath set temperature), the polymer gelledwithin 80 minutes. The polymer had the following structure:

EXAMPLE XXXVII

Poly(4-CPK-FBP) with 1.5 chloromethyl groups per repeat unit (1 gram,prepared as described in Example XXXVI) in 20 milliliters ofN,N-dimethylacetamide was magnetically stirred with sodium acrylate for112 hours at 25° C. The solution was added to methanol using a Waringblender to precipitate the polymer, which was filtered and vacuum dried.About 50 percent of the chloromethyl groups had been replaced withacryloyl groups. The product had the following formula:

EXAMPLE XXXVIII

A polymer of the formula

herein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 16.59grams), bisphenol A (Aldrich 14.18 grams, 0.065 mol), potassiumcarbonate (21.6 grams), anhydrous N,N-dimethylacetamide (100milliliters), and toluene (30 milliliters) were added to the flask andheated to 175° C. (oil bath temperature) while the volatile toluenecomponent was collected and removed. After 4 hours of heating at 175° C.with continuous stirring, the reaction mixture was allowed to cool to25° C. The solidified mass was treated with acetic acid (vinegar) andextracted with methylene chloride, filtered, and added to methanol toprecipitate the polymer, which was collected by filtration, washed withwater, and then washed with methanol. The yield of vacuum dried product,poly(4-FPK-BPA), was 12.22 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 5,158, M_(peak) 15,080, M_(w) 17,260,and M_(z+1) 39,287. To obtain a lower molecular weight, the reaction canbe repeated with a 15 mol % offset in stoichiometry.

EXAMPLE XXXIX

Poly(vinyl benzyl chloride) with a weight average molecular weight of55,000 (obtained from Scientific Polymer Products, Ontario, N.Y., 10grams) in N,N-dimethylacetamide (71 milliliters) and sodium acrylate(5.71 grams) were magnetically stirred in a 250 milliliter amber bottle.The amount of substitution over time was measured using ¹H NMRspectrometry with the following results (the percent substitution ofvinyl benzyl chloride groups to form vinyl benzyl acrylate groups isgiven in parentheses): 2 days (13%); 6 days (36%); 7 days (40%); 8 days(43%); 9 days (47%); 10 days (51%); 14 days (60%); 16 days (65%); 17days (67%); and 21 days (71.2%). The optimum amount of acrylate groupsfor photoresist applications is from about 0.8 to about 2milliequivalents per gram, although amounts outside these ranges can beused. The optimum weight average molecular weight is expected to belower than the 55,000 used in this instance, and preferably is about20,000. Polydispersities (M_(w)/M_(n)) preferably are as near aspossible to 1. Thick films at 30 microns were patterned at 600 dots perinch resolution.

EXAMPLE XL

4′-Methylbenzoyl-2,4-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added toluene (152 grams). The oil bathtemperature was raised to 130° C. and 12.5 grams of toluene wereremoved. There was no indication of water. The flask was removed fromthe oil bath and allowed to cool to 25° C. 2,4-Dichlorobenzoyl chloride(0.683 mol, 143 grams) was added to form a solution. Thereafter,anhydrous aluminum chloride (0.8175 mol, 109 grams) was addedportion-wise over 15 minutes with vigorous gas evolution of hydrochloricacid as determined by odor. The solution turned orange-yellow and thenred. The reaction was stirred for 16 hours under argon, and on removingthe solvent, a solid lump was obtained. The mass was extracted withmethylene chloride (1 liter), which was then dried over potassiumcarbonate and filtered. The filtrate was concentrated using a rotaryevaporator and a vacuum pump to yield an oil which, upon cooling, becamea solid crystalline mass. Recrystallization from methanol (1 liter) at−15° C. gave 82.3 grams of 4′-methylbenzoyl-2,4-dichlorobenzene (meltingpoint 55-56° C.) in the first crop, 32 grams of product (from 500milliliters of methanol) in the second crop, and 16.2 grams of productin the third crop. The total recovered product was 134.7 grams in 65.6%yield.

EXAMPLE XLI

Benzoyl-2,4-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, stopper and situatedin an oil bath was added benzene (200 grams). The oil bath temperaturewas raised to 100° C. and 19 grams of benzene were removed. There was noindication of water. The flask was removed from the oil bath and allowedto cool to 25° C. 2,4-Dichlorobenzoyl chloride (0.683 mol, 143 grams)was added to form a solution. Thereafter, anhydrous aluminum chloride(0.8175 mol, 109 grams) was added portion-wise over 15 minutes withvigorous gas evolution. Large volumes of hydrochloric acid were evolvedas determined by odor. The solution turned orange-yellow and then red.The reaction was stirred for 16 hours under argon and was then added to1 liter of ice water in a 2-liter beaker. The mixture was stirred untilit became white and was then extracted with methylene chloride (1liter). The methylene chloride layer was dried over sodium bicarbonateand filtered. The filtrate was concentrated using a rotary evaporatorand a vacuum pump to yield an oil which, upon cooling, became a solidcrystalline mass (154.8 grams). Recrystallization from methanol gave133.8 grams of benzoyl-2,4-dichlorobenzene as white needles (meltingpoint 41-43° C.) in the first crop.

EXAMPLE XLII

2,5-Dichlorobenzoyl chloride was prepared as follows. To a 2-liter,3-neck round-bottom flask situated in an ice bath and equipped with anargon inlet, condenser, and mechanical stirrer was added2,5-dichlorobenzoic acid (93.1 grams) in 400 milliliters ofdichloromethane to form a slurry. Thionyl chloride (85 grams) in 68grams of dichloromethane was then added and the mixture was stirred at25° C. The mixture was then gradually heated and maintained at refluxfor 16 hours. Thionyl chloride was subsequently removed using a Claisendistillation take-off head with heating to greater than 80° C. Thereaction residue was transferred to a 500 milliliter 1-neck round bottomflask and then distilled using a Kugelrohr apparatus and a vacuum pumpat between 70 and 100° C. at 0.1 to 0.3 mm mercury to obtain 82.1 gramsof 2,5-dichlorobenzoyl chloride, trapped with ice bath cooling as ayellow-white solid.

EXAMPLE XLIII

Benzoyl-2,5-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added benzene (140 grams). The oil bathtemperature was raised to 100° C. and 19 grams of benzene were removed.There was no indication of water. The flask was removed from the oilbath and allowed to cool to 25° C. 2,5-Dichlorobenzoyl chloride (92.6grams), prepared as described in Example XLII, was added to form asolution. Thereafter, anhydrous aluminum chloride (0.8175 mol, 109grams) was cautiously added portion-wise over 15 minutes with vigorousgas evolution. Large volumes of hydrochloric acid were evolved asdetermined by odor. The solution turned orange-yellow and then red. Thereaction was stirred for 16 hours under argon and was then added to 1liter of ice water in a 2-liter beaker. The mixture was stirred until itbecame white and was then extracted with methylene chloride (1 liter).The methylene chloride layer was dried over sodium bicarbonate andfiltered. The filtrate was concentrated using a rotary evaporator and avacuum pump to yield crystals (103.2 grams). Recrystallization frommethanol gave benzoyl-2,5-dichlorobenzene as white needles (meltingpoint 85-87° C.).

EXAMPLE XLIV

4′-Methylbenzoyl-2,5-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added toluene (200 grams). Thereafter,anhydrous aluminum chloride (64 grams) was cautiously added portion-wiseover 15 minutes with vigorous gas evolution. Large volumes ofhydrochloric acid were evolved as determined by odor. The solutionturned orange-yellow and then red. The reaction was stirred for 16 hoursunder argon and was then added to 1 liter of ice water in a 2-literbeaker. The mixture was stirred until it became white and was thenextracted with methylene chloride (1 liter). The methylene chloridelayer was dried over sodium bicarbonate and filtered. The filtrate wasconcentrated using a rotary evaporator and a vacuum pump to yieldcrystals. Recrystallization from methanol gave 37.6 grams of4′-methylbenzoyl-2,5-dichlorobenzene as light-yellow needles (meltingpoint 107-108° C.).

EXAMPLE XLV

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. Under argon in a glove bag, the following reagents werecombined in a 500 milliliter, 3-neck, round-bottom flask equipped withan argon inlet, column, mechanical stirrer, and stopper: Nickeldichloride (0.324 grams), triphenylphosphine 15.7 grams, heated to 200°C. before use), 2,2′-bipyridine (0.391 grams), zinc (16.1 grams, treatedwith glacial acetic acid, washed with diethyl ether and vacuum driedbefore use), and benzoyl-2,4-dichlorobenzene (12.5 grams, prepared asdescribed in Example XLI) in 43.9 grams of N-methylpyrrolidinone,freshly distilled from sodium hydride. The green mixture was heated to90° C. oil bath set temperature. Within 20 minutes, the reaction mixtureturned red-brown and became more red with time. After 16 hours ofreaction at 90° C. with constant stirring, the mixture was added tomethanol and hydrochloric acid, and the polymer that precipitated wascollected, washed with water, and then washed with methanol. The yieldwas 8.8 grams (70.4%) of vacuum dried polymer with a M_(n) 1626, M_(p)1620, M_(w) 2077, and M_(z) 2643, as determined with gel permeationchromatography.

EXAMPLE XLVI

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. Under argon in a glove bag, the following reagents werecombined in a 500 milliliter, 3-neck, round-bottom flask equipped withan argon inlet, column, mechanical stirrer, and stopper: Nickeldichloride (Alpha high quality, 0.2 grams), triphenylphosphine (10.8grams, vacuum dried), 2,2′-bipyridine (0.26 grams, vacuum dried), zinc(Cerac high purity, 14.7 grams), and4′-methylbenzoyl-2,4-dichlorobenzene (20 grams, prepared as described inExample XL) in 50 milliliters of N,N-dimethylacetamide. The mixture washeated to between 70 and 80° C. oil bath set temperature. Within 20minutes, the reaction mixture turned red-brown and became more red withtime. After 16 hours of reaction at 80° C. with constant stirring, themixture was added to methanol and hydrochloric acid, and the polymerthat precipitated was collected, washed with water, and then washed withmethanol. The yield was 14.4 grams (72.0%) of vacuum dried polymer witha M_(n) 3277, M_(p) 5553, M_(w) 6001, and M_(z) 9841, as determined withgel permeation chromatography.

EXAMPLE XLVII

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. Under argon in a glove bag, the following reagents werecombined in a 500 milliliter, 3-neck, round-bottom flask equipped withan argon inlet, column, mechanical stirrer, and stopper: Nickeldichloride (Alpha high quality, 0.2 grams), triphenylphosphine (10.8grams, vacuum dried), 2,2′-bipyridine (0.27 grams, vacuum drieci), zinc(Cerac high purity, 14.4 grams), and4′-methylbenzoyl-2,5-dichlorobenzene (20 grams, prepared as described inExample XLIV) in 50 milliliters of N,N-dimethylacetamide. The mixturewas heated to between 70 and 80° C. oil bath set temperature. Within 20minutes, the reaction mixture turned red-brown and became more red withtime. After 16 hours of reaction at 80° C. with constant stirring, themixture was added to methanol and hydrochloric acid, and the polymerthat precipitated was collected, washed with water, and then washed withmethanol. The yield was 16.6 grams (83.0%) of vacuum dried, light-yellowpolymer with a M_(n) 9,460, M_(p) 29,312, M_(w) 32,487, and M_(z)78,024, as determined with gel permeation chromatography.

EXAMPLE XLVIII

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. Under argon in a glove bag, the following reagents werecombined in a 500 milliliter, 3-neck, round-bottom flask equipped withan argon inlet, column, mechanical stirrer, and stopper: Nickeldichloride (Alpha high quality, 0.2 grams), triphenylphosphine (10.8grams, vacuum dried), 2,2′-bipyridine (0.27 grams, vacuum dried), zinc(Cerac high purity, 15 grams), and N,N-dimethylacetamide (50milliliters). One hour later, 4′-methylbenzoyl-2,4-dichlorobenzene (20grams, prepared as described in Example XL) in 60 milliliters ofN,N-dimethylocetomide were added with stirring. The mixture was heatedto between 70 and 80° C. oil bath set temperature. Within 20 minutes,the reaction mixture turned red-brown and became more red with time.After 20 hours of reaction at 80° C. with constant stirring, the mixturewas added to methanol and hydrochloric acid, and the polymer thatprecipitated was collected, washed with water, and then washed withmethanol. The yield was 14.2 grams (71.0%) of vacuum dried polymer witha M_(n) 3,732, M_(p) 7,199, M_(w) 7,300, and M_(z) 12,333, as determinedwith gel permeation chromatography.

EXAMPLE XLIX

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 250 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4′-Methylbenzoyl-2,4-dichlorobenzene (0.0325 mol, 8.6125 grams, preparedas described in Example XL), bis-phenol A (Aldrich 23,965-8, 0.035 mol,7.99 grams), potassium carbonate (10.7 grams), anhydrousN,N-dimethylacetamide (60 milliliters), and toluene (60 milliliters,49.1 grams) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction product was filtered and the filtrate was added to methanolto precipitate the polymer. The wet polymer cake was isolated byfiltration, washed with water, then washed with methanol, and thereaftervacuum dried. The polymer (7.70 grams, 48% yield) was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,898, M_(peak) 2,154, M_(w) 2,470,M_(z) 3,220, and M_(z+1) 4,095.

EXAMPLE L

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedby repeating the process of Example XLIX except that the4′-methylbenzoyl-2,4-dichlorobenzene starting material was replaced with8.16 grams (0.0325 mol) of benzoyl-2,4-dichlorobenzene, prepared asdescribed in Example XLI, and the oil bath was heated to 170° C. for 24hours.

EXAMPLE LI

A polymer having acryloylmethyl pendant groups thereon was prepared asfollows. The polymer prepared as described in Example XLIX (5 grams) in1,1,2,2-tetrachloroethane (50 milliliters, 80.95 grams),paraformaldehyde (2.5 grams), p-toluenesulfonic acid monohydrate (0.5gram), acrylic acid (7.9 grams) and crushed 4-methoxyphenol (MEHQ, 0.2gram) were charged in a 6.5 fluid ounce beverage bottle equipped with amagnetic stirrer. The bottle was stoppered with a rubber septum and wasthen heated to 105° C. in a silicone oil bath under argon using a needleinlet. The argon needle inlet was removed when the oil bath achieved 90°C. Heating at 105° C. was continued with constant magnetic stirring for1.5 hours. More MEHQ (0.2 gram) in 1 milliliter of tetrachloroethane wasthen added by syringe, and heating at 105° C. with stirring wascontinued for 1.5 hours longer. The reaction mixture was initially acloudy suspension which became clear on heating. The reaction vessel wasimmersed as much as possible in the hot oil bath to prevent condensationof paraformaldehyde onto cooler surfaces of the reaction vessel. Thereaction mixture was then allowed to return to 25° C. and was filteredthrough a 25 to 50 micron sintered glass Buchner funnel. The reactionsolution was added to methanol (1 gallon) to precipitate the polymerwith acryloyl methyl group for every four repeat units.

The acryloylmethylated polymer was then dissolved in methylene chlorideand reprecipitated into methanol (1 gallon) to yield grams of fluffywhite solid. The polymer was soluble in chlorinated solvents and polaraprotic solvents, but insoluble in acetone and alcohols. Films of thepolymer were thermally ramp cured at 0.2° C. per minute until 260° C.was achieved, and then maintained at 260° C. for 3 hours longer beforethe films were allowed to cool to 25° C.

Photoactive compositions were made by preparing a 50 weight percentsolids solution in N-methylpyrrolidinone using excess methylene chlorideas a volatile diluent which was later removed. Michler's ketone wasadded to the formulation at between 0.5 and 1 weight percent of theresin solids. The solution was filtered and the methylene chloride wasremoved using a rotary evaporator. Solutions at approximately 37 weightpercent solids were used to cast dried films of the polymer onto siliconwafers which had previously been treated with a silane adhesion promoterand heated at 70° C. for 10 minutes. The wet films were dried at 80° C.for 20 minutes before exposure to ultraviolet light. Ideal exposureconditions were about 2,500 milliJoules/cm². After exposure, the filmswere heated to 80° C. for 5 minutes before development withN-methylpyrrolidinone, cyclohexane, and methanol. Ten micron spin coatedfilms were patterned at 300 dots per inch resolution.

EXAMPLE LII

The process of Example LI was repeated except that the polymer preparedas described in Example L was used. Similar results were obtained.

EXAMPLE LIII

A polymer of the formula

wherein n is about 9 (hereinafter referred to as poly(4-CPK-BPA)) wasprepared as follows. A 500 milliliter, 3-neck round-bottom flaskequipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), bis-phenol A (Aldrich23.965-8, 15.98 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitate apolymer which was collected by filtration, washed with water, and thenwashed with methanol. The vacuum dried product, poly(4-CPK-BPA), was10.34 grams that was analyzed by gel permeation chromatography (gpc)(elution solvent was tetrahydrofuran) with the following results: M_(n)4464, M_(peak) 7580, M_(w) 7930, M_(z) 12,300, and M_(z+1) 16,980. Theglass transition temperature of the polymer was 155° C. as determinedusing differential scanning calorimetry at a heating rate of 20° C. perminute. Solution cast films from methylene chloride were clear, tough,and flexible. As a result of the stoichiometries used in the reaction,it is believed that this polymer had end groups derived from bis-phenolA.

To poly(4-CPK-BPA) (10 grams) thus prepared in chloroform (90milliliters, extracted with water, dried over Drierite, filtered, andfreshly distilled from Drierite) that contained a 50% molar excess oftriethylamine (distilled over sodium hydride) was added 4-ethynylbenzoylchloride (50 mol % excess) in chloroform (10 milliliters) with stirringunder argon. After 3 hours, the polymer was added to methanol using aWaring blender to precipitate ethynyl-terminated poly(4-CPK-BPA), whichwas collected by filtration and was vacuum dried. The polymer wasbelieved to be of the following formula:

wherein n is about 9.

Thereafter, ethynyl terminated poly(4-CPK-BPA) (10 grams) thus preparedin 1,1,2,2-tetrachloroethane (100 milliliters, 161.9 grams),paraformaldehyde (5 grams), p-toluenesulfonic acid monohydrate (1 gram),acrylic acid (15.8 grams), and crushed 4-methoxyphenol (MEHQ, 0.2 gram)were charged in a 6.5 fluid ounce beverage bottle equipped with amagnetic stirrer. The bottle was stoppered with a rubber septum and wasthen heated to 105° C. in a silicone oil bath under argon using a needleinlet. The argon needle inlet was removed when the oil bath achieved 90°C. Heating at 105° C. was continued with constant magnetic stirring for1.5 hours. More MEHQ (0.2 gram) in 1 milliliter of1,1,2,2-tetachloroethane was then added by syringe, and heating at 105°C. with stirring was continued for 1.5 hours longer. The reactionmixture was initially a cloudy suspension which became clear on heating.The reaction vessel was immersed as much as possible in the hot oil bathto prevent condensation of paraformaldehyde onto cooler surfaces of thereaction vessel. The reaction mixture was then allowed to return to 25°C. and was filtered through a 25 to 50 micron sintered glass Buchnerfunnel. The reaction solution was added to methanol (1 gallon) toprecipitate the polymer designated poly(acryloylmethyl-4-CPK-BPA), ofthe formula

wherein n is about 9. ¹H NMR spectrometry was used to identifyapproximately 1 acryloylmethyl group for every four monomer (4-CPK-BPA)repeat units (i.e., a degree of acryloylation of 0.25). Thepoly(acryloylmethyl-4-CPK-BPA) was then dissolved in methylene chlorideand reprecipitated into methanol (1 gallon) to yield 10 grams of fluffywhite solid. The polymer was soluble in chlorinated solvents and polaraprotic solvents, but insoluble in acetone and alcohols. Films of thepolymer were thermally ramp cured at 0.2° C. per minute until 260° C.was achieved, and then maintained at 260° C. for 3 hours longer beforethe films were allowed to cool to 25° C.

Photoactive compositions were made by preparing a 50 weight percentsolids solution in N-methylpyrrolidinone using excess methylene chlorideas a volatile diluent which was later removed. Michler's ketone wasadded to the formulation at between 0.5 and 1 weight percent of theresin solids. The solution was filtered and the methylene chloride wasremoved using a rotary evaporator. Solutions at approximately 37 weightpercent solids were used to cast dried films of the polymer onto siliconwafers which had previously been treated with a silane adhesion promoterand heated at 70° C. for 10 minutes. The wet films were dried at 80° C.for 20 minutes before exposure to ultraviolet light. Ideal exposureconditions were about 2,500 milliJoules/cm². After exposure, the filmswere heated to 80° C. for 5 minutes before development withN-methylpyrrolidinone, cyclohexane, and methanol. Thermal curing wasthen carried out by heating the films to 300° C. Ten micron spin coatedfilms were patterned at 300 dots per inch resolution.

EXAMPLE LIV

Chloromethylated phenoxy resins, polyethersulfones, and polyphenyleneoxides are prepared by reacting the unsubstituted polymers with tintetrachloride and 1-chloromethoxy-4-chlorobutane as described by W. H.Daly et al. in Polymer Preprints, 20(1), 835 (1979), the disclosure ofwhich is totally incorporated herein by reference. The chloromethylationof polyethersulfone and polyphenylene oxide can also be accomplished asdescribed by V. Percec et al. in Makromol. Chem., 185, 2319 (1984), thedisclosure of which is totally incorporated herein by reference.

Acryloylated polymers are then prepared as follows:

The chloromethylated polymers are acryloylated by allowing thechloromethylated polymer (10 grams) in N,N-dimethylacetamide (71milliliters) to react with acrylic acid sodium salt (5.14 grams) forbetween 3 and 20 days, depending on the degree of acryloylation desired.Longer reaction times result in increased acrylate functionality.

EXAMPLE LV

A polymer of the formula

wherein n is about 9 (hereinafter referred to as poly(4-CPK-BPA)) havingphenolic end groups is prepared as described in Example LIII. In a flaskequipped with a reflux condenser are placed 0.20 mol of phenolterminated poly(4-CPK-BPA), 0.23 mol of allyl bromide, 0.20 mole ofpotassium carbonate, and 200 milliliters of N,N-dimethylacetamide. Thereaction mixture is heated at 60° C. for 16 hours, cooled, and filtered.The filtrate is added to methanol to precipitate the polymer,poly(4-CPK-BPA) with allyl end groups.

EXAMPLE LVI

To allyl terminated polymer prepared as described in Example LV (10grams) in 200 grams of methylene chloride is added drop-wisem-chloroperoxybenzoic acid (2 equivalents) in 25 grams of methylenechloride over 15 minutes. The reaction solution is magnetically stirredfor 16 hours, and then is added to 5% aqueous sodium bicarbonate. Themethylene chloride layer is removed using a rotary evaporator, and thepolymer that coagulates is dissolved in methylene chloride, precipitatedinto methanol, filtered and vacuum dried to yield 8 grams of epoxyterminated poly(4-CPK-BPA).

EXAMPLE LVII

A hydroxy-terminated polyether sulfone is made with a number averagemolecular weight of 2,800 following the procedure described in V. Percecand B. C. Auman, Makromol. Chem, 85, 617 (1984), the disclosure of whichis totally incorporated herein by reference. This polymer ischloromethylated as described in V. Peircec and B. C. Auman, Makromol.Chem., 185, 2319 (1984), the disclosure of which is totally incorporatedherein by reference. The polyether sulfone with 1.5 chloromethyl groupsper repeat unit (10 grams) in 71 milliliters of N,N-dimethylacetamide ismagnetically stirred with sodium acrylate (5.74 grams) for 112 hours at25° C. The mixture is centrifuged, and the supernate is added tomethanol using a Waring blender to precipitate the polymer, which isfiltered and vacuum dried. About 50% of the chloromethyl groups arereplaced with acryloyl groups. The product has the following formula:

This polymer when formulated at 40 weight percent solids with Michler'sketone at about 0.5 weight percent with 3 weight percent benzophenone isa suitable photoresist for preparing thermal ink jet heads. A heaterwafer with a phosphosilicate glass layer is spin coated with a solutionof Z6020 adhesion promoter (0.01 weight percent in methanol (95 parts)and water (5 parts), available from Dow Corning) at 3000 revolutions perminute for 10 seconds and dried at 100° C. for between 2 and 10 minutes.The wafer is then allowed to cool at 25° C. over 5 minutes before spincoating the polymer photoresist onto the wafer at between 1000 and 3000revolutions per minute for between 30 and 60 seconds. The photoresistsolution is made by dissolving polyarylene ether sulfone with 0.75acryloyl groups and 0.75 chloromethyl groups per repeat unit and aweight average molecular weight of 25,000 in N-methylpyrrolidinone at 40weight percent solids with Michler's ketone (1.2 parts per every 10parts of 40 weight percent solids solution). The film is heated (softbaked) in an oven for between 10 and 15 minutes at 70° C. After coolingto 25° C. over 5 minutes, the film is covered with a mask and exposed to365 nanometers ultraviolet light, amounting to between 150 and 1500milliJoules per cm². The exposed wafer is then heated at 70° C. for 2minutes post exposure bake, followed by cooling to 25° C. over 5minutes. The film is developed with 6:4 chloroform/cyclohexanonedeveloper, washed with 9:1 hexanes/cyclohexanone and then dried at 70°C. for 2 minutes. A second developer/wash cycle is carried out ifnecessary to obtain a wafer with clean features. The processed wafer istransferred to an oven at 25° C., and the oven temperature is raisedfrom 25 to 90° C. at 2° C. per minute. The temperature is maintained at90° C. for 2 hours, and then increased to 260° C. at 2° C. per minute.The oven temperature is maintained at 260° C. for 2 hours, and the ovenis then turned off and the temperature is allowed to cool gradually to25° C. When thermal cure of the photoresist films is carried out underinert atmosphere such as argon or nitrogen, there is markedly reducedoxidation of the developed film and improved thermal and hydrolyticstability of the resultant devices. Moreover, adhesion is improved tothe underlying substrate. The heat cure of the first developed layer canbe stopped between 80 and 260° C. before the second layer is spin coatedon top. A second thicker layer is deposited by repeating the aboveprocedure a second time. This process is intended to be a guide in thatprocedures can be outside the specified conditions depending on filmthickness and photoresist molecular weight. Films at 30 microns aredevelopable with clean features at 300 dots per inch.

EXAMPLE LVIII

Poly(4-CPK-BPA) is made with a number average molecular weight of 2,800as follows. A 5-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper is situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)are added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component is collected and removed. Afterhours of heating 30 hours at 175° C. with continuous stirring, thereaction mixture is filtered to remove insoluble salts, and theresultant solution is added to methanol (5 gallons) to precipitate thepolymer. The polymer is isolated by filtration, and the wet filter cakeis washed with water (3 gallons) and then with methanol (3 gallons). Theyield is about 360 grams of vacuum dried polymer. It is believed that ifthe molecular weight of the polymer is determined by gel permeationchromatography (gpc) (elution solvent was tetrahydrofuran) the followingresults will be obtained: M_(n) 2,800, M_(peak) 5,800, M_(w) 6,500,M_(z) 12,000 and M_(z+1) 17,700. As a result of the stoichiometries usedin the reaction, it is believed that this polymer has end groups derivedfrom bis-phenol A.

The polymer is then chloromethylated as follows. A solution ofchloromethyl ether in methyl acetate is made by adding 282.68 grams (256milliliters) of acetyl chloride to a mixture of dimethoxy methane (313.6grams, 366.8 milliliters) and methanol (10 milliliters) in a 5-liter3-neck round-bottom flask equipped with a mechanical stirrer, argoninlet, reflux condenser, and addition funnel. The solution is dilutedwith 1,066.8 milliliters of 1,1,2,2-tetrachloroethane and then tintetrachloride (2.4 milliliters) is added via a gas-tight syringe, alongwith 1,1,2,2-tetrachloroethane (133.2 milliliters) using an additionfunnel. The reaction solution is heated to 50° C. and a solution ofpoly(4-CPK-BPA) (160.8 grams) in 1,1,2,2-tetrachloroethane (1,000milliliters) is rapidly added. The reaction mixture is then heated toreflux with an oil bath set at 110° C. After four hours reflux withcontinuous stirring, heating is discontinued and the mixture is allowedto cool to 25° C. The reaction mixture is transferred in stages to a 2liter round bottom flask and concentrated using a rotary evaporator withgentle heating up to 50° C. and reduced pressure maintained with avacuum pump trapped with liquid nitrogen. The concentrate is added tomethanol (6 gallons) to precipitate the polymer using a Waring blender.The polymer is isolated by filtration and vacuum dried to yield 200grams of poly(4-CPK-BPA) with 1.5 chloromethyl groups per repeat unit.Solvent free polymer is obtained by reprecipitation of the polymer (75grams) dissolved in methylene chloride (500 grams) into methanol (3gallons) followed by filtration and vacuum drying to yield 70.5 grams(99.6% yield) of solvent free polymer. To a solution of thechloromethylated poly(4-CPK-BPA) (192 mmol of chloromethyl groups) in 80milliliters of dioxane is added 12 grams (46 mmol) oftriphenylphosphine. After 15 hours of reflux with mechanical stirringand cooling to 25° C., the polymer solidifies and the mixture isextracted with diethyl ether using a Waring blender. The yellow productis filtered, washed several times with diethyl ether, and vacuum dried.To a solution of triphenylphosphonium chloride salt of chloromethylatedpoly(4-CPK-BPA) (14 mmol of phosphonium groups) in 200 milliliters ofmethanol, 2 milliliters of Triton B (40 weight percent aqueous solution)and 11.5 milliliters (140 mmol) of formaldehyde (37 weight percentaqueous solution) are added. The stirred reaction mixture is treatedslowly with 36 milliliters of 50 weight percent aqueous sodiumhydroxide. A precipitate starts to appear on addition of the first dropsof sodium hydroxide solution. After 10 hours of reaction at 25° C., theprecipitate is filtered and vacuum dried. The separated polymer isdissolved in methylene chloride, washed several times with water, andthen precipitated with methanol. Alternatively, to a solution ofsolution of 1.8 mmol of phosphonium groups of the triphenylphosphoniumchloride salt chloromethylated poly(4-CPK-BPA) in 40 milliliters ofmethylene chloride at ice-water temperature, 1.6 milliliters (19.5 mmol)of formaldehyde (37 weight percent aqueous solution), and 0.4milliliters of Triton-B (40 weight percent aqueous solution) is added.The stirred reaction mixture is treated slowly with 5 milliliters (62.5mmol) of 50 weight percent aqueous sodium hydroxide. After all thehydroxide solution is added, the reaction mixture is allowed to react at25° C. After 7 hours of reaction, the organic layer is separated, washedwith dilute hydrochloric acid, then washed with water, and thenprecipitated into methanol from chloroform. The polymer has thestructure:

The polymer can be further treated with m-chloroperoxybenzoic acid toform an epoxidized product with the following formula:

EXAMPLE LIX

A solution of poly(4-CPK-BPA) with pendant vinyl groups (prepared asdescribed in Example LVIII, 12.5 mmol of vinyl groups) in 30 millilitersof methylene chloride is cooled in an ice-water bath and titrated withbromine until an orange color persists, indicating addition of bromineacross the double bond and conversion of the ethylene groups to1,2-bromoethyl groups. After 30 minutes of stirring at 25° C., thepolymer is precipitated with methanol, filtered, and vacuum dried. To avigorously stirred mixture of 3 mmol of 1,2-bromoethyl groups of1,2-dibromoethylated poly(4-CPK-BPA) in 30 milliliters of methylenechloride and 10 milliliters of 50 weight percent aqueous sodiumhydroxide at 25° C., 3 grams (9 mmol) of tetrabutylammonium hydroxideare added. An exothermic reaction takes place, indicating generation ofNaBr and H₂O and conversion of the 1,2-bromoethyl groups to ethynylgroups. After 1.5 hours of stirring at 25° C., the organic portion iswashed with water, dilute hydrochloric acid, then water, and thenmethanol. The white poly(4-CPK-BPA) is precipitated from methylenechloride into methanol. Alternatively, to a stirred solution at 25° C.,3 mmol of 1,2-dibromoethyl groups of bromoethylated poly(4-CPK-BPA) in20 milliliters of DMSO, 1.4 grams (12 mmol) of potassium t-butoxide in 5milliliters of dimethyl sulfoxide is added. The reaction mixture isstirred at 25° C. for 1 hour and then precipitated into methanol,filtered, and vacuum dried. The soluble part of this polymer isextracted with methylene chloride or chloroform and precipitated intomethanol. The product has the formula

Polymers with the following formulae can also be made by the proceduresdescribed hereinabove:

In each instance, the polymer is first substituted with the ethynyl orvinyl groups and then substituted with the unsaturated ester groups. Thepolymer can be substituted with vinyl groups by reacting thehaloalkylated polymer with triphenyl phosphine to generate thetriphenylphosphonium-substituted polymer, followed by reaction of thetriphenylphosphonium-substituted polymer with formaldehyde in thepresence of a base to generate the vinyl-substituted polymer. Ethynyland vinyl terminated poly(4-CPK-BPA) can be made by substitutingpoly(4-CPK-BPA) for hydroxy terminated polyether sulfone in theprocedures described by V. Percec and B. C. Auman, Makromol. Chem., 185,1867 (1984), the disclosure of which is totally incorporated herein byreference.

EXAMPLE LX

LaRC PETI (obtained from NASA Langley Research Center), a polymer blendcontaining 85 percent by weight of a polymer of the formula

with ethynyl terminal end groups and 15 percent by weight of a polymerof the formula

with ethynyl terminal end groups, was spin coated onto silicon wafersand thermally imidized in a nitrogen purged environment. Thereafler,pieces of each polyimide coated wafer were soaked in a solution of 1Molar tetramethyl ammonium hydroxide at 40° C. and at 60° C.Subsequently, an ion exchange reaction was carried out with a cesiumsalt to label the hydrolyzed regions. For comparison purposes, the sameprocedures were carried out on silicon wafers spin coated with LaRC 8515(obtained from NASA Langley Research Center), a blend of the samecomposition as LaRC PETI except that the polymers did not have ethynylterminal groups. The depth of hydrolysis of each sample was measuredusing Rutherford Backscattering, from which a rate of hydrolysis and anactivation energy for the reaction were calculated. The results were asfollows:

hydrolysis rate at hydrolysis rate at 40° C. (Angstroms 60° C.(Angstroms E_(act) polymer per hour) per hour) (KJ/mole) LaRC 8515 66540  94 LaRC PETI 35 450 108

As the results indicate, the hydrolytic rate was faster for the LaRC8515 than for the ethynyl-terminated LaRC PETI. While it is not wishedto be limited to any particular theory, it is believed that while thetwo materials have the same backbone structure, the PETI is endcappedwith a reactive endgroup which, it is believed, promotes crosslinkingduring the thermal imidization process, and that this crosslinkingreduced the rate of hydrolytic damage.

Other embodiments and modifications of the present invention may occurto those skilled in the art subsequent to a review of the informationpresented herein; these embodiments and modifications, as well asequivalents thereof, are also included within the scope of thisinvention.

What is claimed is:
 1. A crosslinked or chain extended polymer formed bycrosslinking or chain extending a precursor polymer with a weightaverage molecular weight of from about 1,000 to about 100,000, saidprecursor polymer having terminal end groups and monomer repeat units,said crosslinking or chain extension occurring through first,photosensitivity-imparting substituents pendant from at least some ofthe monomer repeat units of the precursor polymer which form crosslinksor chain extensions in the precursor polymer upon exposure to actinicradiation, said precursor polymer also containing a second, thermalsensitivity-imparting substituent, present as (1) at least one terminalend group, (2) a substituent pendant from one or more of the monomerrepeat units, or (3) a combination of (1) and (2), which enables furthercrosslinking or chain extension of the precursor polymer upon exposureto temperatures of about 140° C. and higher subsequent to exposure toactinic radiation at a wavelength sufficient to cause crosslinking orchain extension of the precursor polymer through the first,photosensitivity-imparting substituents, wherein the first substituentis not the same as the second substituent, said second, thermalsensitivity-imparting substituent being selected from the groupconsisting of ethynyl groups, allyl groups, vinyl groups, vinyl ethergroups, benzocyclobutene groups, phenolic groups, maleimide groups,biphenylene groups, 5-norbornene-2,3-dicarboximido groups, and mixturesthereof, provided that when the thermal sensitivity imparting groups arephenolic groups, either halomethyl groups or hydroxymethyl groups arepresent (A) on the precursor polymer having the phenolic thermalsensitivity imparting groups, (B) on a second polymer admixed with theprecursor polymer having the phenolic thermal sensitivity impartinggroups, or (C) on a monomeric species admixed with the precursor polymerhaving the phenolic thermal sensitivity imparting groups, said precursorpolymer being selected from the group consisting of polysulfones,polyphenylenes, polyether sulfones, polyimides, polyamide imides,polyarylene ethers, polyphenylene sulfides, polyarylene ether ketones,phenoxy resins, polycorbonates, polyether imides, polyquinoxalines,polyquinolines, polybenzimidazoles, polybenzoxazoles,polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixturesthereof, said crosslinking or chain extending being effected by (i)first exposing the precursor polymer to actinic radiation at awavelength sufficient to cause crosslinking or chain extension of theprecursor polymer through the first, photosensitivity-impartingsubstituents, and (ii) exposing the precursor polymer to temperatures ofabout 140° C. or higher subsequent to exposure to actinic radiation tocause further crosslinking or chain extension of the precursor polymerthrough the second, thermal sensitivity-imparting substituent, whereineither (a) the first, photosensitivity-imparting substituent and thesecond, thermal sensitivity-imparting substituent are selected so thatthe second, thermal sensitivity imparting group does not react orcrosslink when exposed to actinic radiation at a level to which thefirst, photosensitivity-imparting group is sensitive, or (b) photocuringis halted while at least some of the second, thermal sensitivityimparting groups remain intact and unreacted or uncrosslinked on theprecursor polymer.
 2. A crosslinked or chain extended polymer accordingto claim 1 wherein the precursor polymer contains at least about 0.25photosensitivity-imparting groups per repeat monomer unit.
 3. Acrosslinked or chain extended polymer according to claim 1 wherein theprecursor polymer is substituted with photosensitivity-imparting groupsto a degree of least about 0.5 milliequivalents per gram of precursorpolymer.
 4. A crosslinked or chain extended polymer according to claim 1wherein the precursor polymer contains at least about 1 thermalsensitivity imparting group per repeat monomer unit.
 5. A crosslinked orchain extended polymer according to claim 1 wherein the precursorpolymer is substituted with thermal sensitivity imparting groups to adegree of least about 0.5 milliequivalents per gram of precursorpolymer.
 6. A crosslinked or chain extended polymer according to claim 1wherein the precursor polymer is substituted with unsaturated esterphotosensitivity-imparting groups.
 7. A crosslinked or chain extendedpolymer according to claim 1 wherein the precursor polymer issubstituted with alkylcarboxymethylene photosensitivity-impartinggroups.
 8. A crosslinked or chain extended polymer according to claim 1wherein the precursor polymer is substituted with epoxyphotosensitivity-imparting groups.
 9. A crosslinked or chain extendedpolymer according to claim 1 wherein the precursor polymer issubstituted with allyl ether photosensitivity-imparting groups.
 10. Acrosslinked or chain extended polymer according to claim 1 wherein theprecursor polymer is substituted with ether photosensitivity-impartinggroups.
 11. A crosslinked or chain extended polymer according to claim 1wherein the precursor polymer is substituted with unsaturated etherphotosensitivity-imparting groups.
 12. A crosslinked or chain extendedpolymer according to claim 1 wherein the precursor polymer issubstituted with unsaturated ammonium photosensitivity-imparting groups.13. A crosslinked or chain extended polymer according to claim 1 whereinthe precursor polymer is substituted with unsaturated phosphoniumphotosensitivity-imparting groups.
 14. A crosslinked or chain extendedpolymer according to claim 1 wherein the precursor polymer issubstituted with hydroxyalkyl photosensitivity-imparting groups.
 15. Acrosslinked or chain extended polymer formed by crosslinking or chainextending a precursor polymer with a weight average molecular weight offrom about 1,000 to about 100,000, said precursor polymer havingterminal end groups and monomer repeat units, said crosslinking or chainextension occurring through first, photosensitivity-impartingsubstituents pendant from at least some of the monomer repeat units ofthe precursor polymer which form crosslinks or chain extensions in theprecursor polymer upon exposure to actinic radiation, said precursorpolymer also containing a second, thermal sensitivity-impartingsubstituent, present as (1) at least one terminal end group, (2) asubstituent pendant from one or more of the monomer repeat units, or (3)a combination of (1) and (2), which enables further crosslinking orchain extension of the precursor polymer upon exposure to temperaturesof about 140° C. and higher subsequent to exposure to actinic radiationat a wavelength sufficient to cause crosslinking or chain extension ofthe precursor polymer through the first, photosensitivity-impartingsubstituents, wherein the first substituent is not the same as thesecond substituent, said crosslinking or chain extending being effectedby (i) first exposing the precursor polymer to actinic radiation at awavelength sufficient to cause crosslinking or chain extension of theprecursor polymer through the first, photosensitivity-impartingsubstituents, and (ii) exposing the precursor polymer to temperatures ofabout 140° C. or higher subsequent to exposure to actinic radiation tocause further crosslinking or chain extension of the precursor polymerthrough the second, thermal sensitivity-imparting substituent, whereineither (a) the first, photosensitivity-imparting substituent and thesecond, thermal sensitivity-imparting substituent are selected so thatthe second, thermal sensitivity imparting group does not react orcrosslink when exposed to actinic radiation at a level to which thefirst, photosensitivity-impairing group is sensitive, or (b) photocuringis halted while at least some of the second, thermal sensitivityimparting groups remain intact and unreacted or uncrosslinked on theprecursor polymer, wherein the precursor polymer is (a) of the formula

wherein x is an integer of 0 or 1, P is a functional group which impartsphotosensitivity to the precursor polymer, T is a functional group whichimparts thermal sensitivity to the precursor polymer, a, b, c, and d areeach integers of 0, 1, 2, 3, or 4, provided that at least one of a, b,c, and d is equal to or greater than 1 in at least some of the monomerrepeat units of the precursor polymer, e, f, g, and h are each integersof 0, 1, 2, 3, or 4, provided that the sum of a+e is no greater than 4,the sum of b+f is no greater than 4, the sum of c+g is no greater than4, and the sum of d+h is no greater than 4, and i and j are eachintegers of 0 or 1, provided that either (1) at least one of e, f, g,and h is equal to or greater than 1 in at least some of the monomerrepeat units of the precursor polymer, or (2) at least one of i and j isequal to 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units; (b) of the formula

wherein x is an integer of 0 or 1, P is a functional group which impartsphotosensitivity to the precursor polymer, T is a functional group whichimparts thermal sensitivity to the precursor polymer, a, b, c, and d areeach integers of 0, 1, 2, 3, or 4, provided that at least one of a, b,c, and d is equal to or greater than 1 in at least some of the monomerrepeat units of the precursor polymer, e, f, g, and h are each integersof 0, 1, 2, 3, or 4, provided that the sum of a+e is no greater than 4,the sum of b+f is no greater than 4, the sum of c+g is no greater than4, and the sum of d+h is no greater than 4, and i and j are eachintegers of 0 or 1, provided that either (1) at least one of e, f, g,and h is equal to or greater than in at least some of the monomer repeatunits of the precursor polymer, or (2) at least one of i and j is equalto 1, A is

or mixtures thereof, B is

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units; or (c) of the formula

wherein x is an integer of 0 or 1, P is a functional group which impartsphotosensitivity to the precursor polymer, T is a functional group whichimparts thermal sensitivity to the precursor polymer, a, b, c, and d areeach integers of 0, 1, 2, 3, or 4, provided that at least one of a, b,c, and d is equal to or greater than 1 in at least some of the monomerrepeat units of the precursor polymer, e, f, g, and h are each integersof 0, 1, 2, 3, or 4, provided that the sum of a+e is no greater than 4,the sum of b+f is no greater than 4, the sum of c+g is no greater than4, and the sum of d+h is no greater than 4, and i and j are eachintegers of 0 or 1, provided that either (1) at least one of e, f, g,and h is equal to or greater than 1 in at least some of the monomerrepeat units of the precursor polymer, or (2) at least one of i and j isequal to 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units.
 16. A crosslinked or chain extended polymeraccording to claim 15 wherein the precursor polymer is substituted withphotosensitivity-imparting groups selected from the group consisting ofunsaturated ester groups, alkylcarboxymethylene groups, epoxy groups,ether groups, unsaturated ammonium groups, unsaturated phosphoniumgroups, hydroxyalkyl groups, or mixtures thereof.
 17. A polymeraccording to claim 15 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 18.A polymer according to claim 15 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 19. A polymer according toclaim 15 wherein the polymer has end groups derived from the “B” groupsof the polymer.
 20. A crosslinked or chain extended polymer according toclaim 15 wherein “A” is selected so that the repeat unit contains abenzophenone moiety.